src/plugins/gbp/gbp_policy.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
  21 /**
  22  * Grouping of global data for the GBP source EPG classification feature
  23  */
  24 typedef struct gbp_policy_main_t_
  25 {
  26   /**
  27    * Next nodes for L2 output features
  28    */
  29   u32 l2_output_feat_next[2][32];
  30 } gbp_policy_main_t;
  31
  32 static gbp_policy_main_t gbp_policy_main;
  33
  34 #define foreach_gbp_policy                      \
  35   _(DENY,    "deny")
  36
  37 typedef enum
  38 {
  39 #define _(sym,str) GBP_ERROR_##sym,
  40   foreach_gbp_policy
  41 #undef _
  42     GBP_POLICY_N_ERROR,
  43 } gbp_policy_error_t;
  44
  45 static char *gbp_policy_error_strings[] = {
  46 #define _(sym,string) string,
  47   foreach_gbp_policy
  48 #undef _
  49 };
  50
  51 typedef enum
  52 {
  53 #define _(sym,str) GBP_POLICY_NEXT_##sym,
  54   foreach_gbp_policy
  55 #undef _
  56     GBP_POLICY_N_NEXT,
  57 } gbp_policy_next_t;
  58
  59 /**
  60  * per-packet trace data
  61  */
  62 typedef struct gbp_policy_trace_t_
  63 {
  64   /* per-pkt trace data */
  65   u32 src_epg;
  66   u32 dst_epg;
  67   u32 acl_index;
  68   u32 allowed;
  69 } gbp_policy_trace_t;
  70
  71 always_inline dpo_proto_t
  72 ethertype_to_dpo_proto (u16 etype)
  73 {
  74   etype = clib_net_to_host_u16 (etype);
  75
  76   switch (etype)
  77     {
  78     case ETHERNET_TYPE_IP4:
  79       return (DPO_PROTO_IP4);
  80     case ETHERNET_TYPE_IP6:
  81       return (DPO_PROTO_IP6);
  82     }
  83
  84   return (DPO_PROTO_NONE);
  85 }
  86
  87 always_inline u32
  88 gbp_rule_l2_redirect (const gbp_rule_t * gu, vlib_buffer_t * b0)
  89 {
  90   const ethernet_header_t *eth0;
  91   const dpo_id_t *dpo;
  92   dpo_proto_t dproto;
  93
  94   eth0 = vlib_buffer_get_current (b0);
  95   /* pop the ethernet header to prepare for L3 rewrite */
  96   vlib_buffer_advance (b0, vnet_buffer (b0)->l2.l2_len);
  97
  98   dproto = ethertype_to_dpo_proto (eth0->type);
  99   dpo = &gu->gu_dpo[GBP_POLICY_NODE_L2][dproto];
 100
 101   /* save the LB index for the next node and reset the IP flow hash
 102    * so it's recalculated */
 103   vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo->dpoi_index;
 104   vnet_buffer (b0)->ip.flow_hash = 0;
 105
 106   return (dpo->dpoi_next_node);
 107 }
 108
 109 always_inline u8
 110 gbp_policy_is_ethertype_allowed (const gbp_contract_t * gc0, u16 ethertype)
 111 {
 112   u16 *et;
 113
 114   vec_foreach (et, gc0->gc_allowed_ethertypes)
 115   {
 116     if (*et == ethertype)
 117       return (1);
 118   }
 119   return (0);
 120 }
 121
 122 static uword
 123 gbp_policy_inline (vlib_main_t * vm,
 124                    vlib_node_runtime_t * node,
 125                    vlib_frame_t * frame, u8 is_port_based)
 126 {
 127   gbp_main_t *gm = &gbp_main;
 128   gbp_policy_main_t *gpm = &gbp_policy_main;
 129   u32 n_left_from, *from, *to_next;
 130   u32 next_index;
 131
 132   next_index = 0;
 133   n_left_from = frame->n_vectors;
 134   from = vlib_frame_vector_args (frame);
 135
 136   while (n_left_from > 0)
 137     {
 138       u32 n_left_to_next;
 139
 140       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 141
 142       while (n_left_from > 0 && n_left_to_next > 0)
 143         {
 144           const ethernet_header_t *h0;
 145           const gbp_endpoint_t *ge0;
 146           const gbp_contract_t *gc0;
 147           gbp_policy_next_t next0;
 148           gbp_contract_key_t key0;
 149           u32 bi0, sw_if_index0;
 150           vlib_buffer_t *b0;
 151           index_t gci0;
 152
 153           gc0 = NULL;
 154           next0 = GBP_POLICY_NEXT_DENY;
 155           bi0 = from[0];
 156           to_next[0] = bi0;
 157           from += 1;
 158           to_next += 1;
 159           n_left_from -= 1;
 160           n_left_to_next -= 1;
 161
 162           b0 = vlib_get_buffer (vm, bi0);
 163           h0 = vlib_buffer_get_current (b0);
 164           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 165
 166           /*
 167            * If the A0bit 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               key0.as_u32 = ~0;
 179               goto trace;
 180             }
 181           /*
 182            * determine the src and dst EPG
 183            */
 184           if (is_port_based)
 185             ge0 = gbp_endpoint_find_itf (sw_if_index0);
 186           else
 187             ge0 = gbp_endpoint_find_mac (h0->dst_address,
 188                                          vnet_buffer (b0)->l2.bd_index);
 189
 190           if (NULL != ge0)
 191             key0.gck_dst = ge0->ge_fwd.gef_epg_id;
 192           else
 193             /* If you cannot determine the destination EP then drop */
 194             goto trace;
 195
 196           key0.gck_src = vnet_buffer2 (b0)->gbp.src_epg;
 197
 198           if (EPG_INVALID != key0.gck_src)
 199             {
 200               if (PREDICT_FALSE (key0.gck_src == key0.gck_dst))
 201                 {
 202                   /*
 203                    * intra-epg allowed
 204                    */
 205                   next0 =
 206                     vnet_l2_feature_next (b0,
 207                                           gpm->l2_output_feat_next
 208                                           [is_port_based],
 209                                           (is_port_based ?
 210                                            L2OUTPUT_FEAT_GBP_POLICY_PORT :
 211                                            L2OUTPUT_FEAT_GBP_POLICY_MAC));
 212                   vnet_buffer2 (b0)->gbp.flags |= VXLAN_GBP_GPFLAGS_A;
 213                 }
 214               else
 215                 {
 216                   gci0 = gbp_contract_find (&key0);
 217
 218                   if (INDEX_INVALID != gci0)
 219                     {
 220                       u32 rule_match_p0, trace_bitmap0;
 221                       fa_5tuple_opaque_t pkt_5tuple0;
 222                       u32 acl_pos_p0, acl_match_p0;
 223                       u8 is_ip60, l2_len0, action0;
 224                       const gbp_rule_t *gu;
 225                       u16 ether_type0;
 226                       const u8 *h0;
 227
 228                       action0 = 0;
 229                       gc0 = gbp_contract_get (gci0);
 230                       l2_len0 = vnet_buffer (b0)->l2.l2_len;
 231                       h0 = vlib_buffer_get_current (b0);
 232
 233                       ether_type0 = *(u16 *) (h0 + l2_len0 - 2);
 234
 235                       if (!gbp_policy_is_ethertype_allowed (gc0, ether_type0))
 236                         {
 237                           /*
 238                            * black list model so drop
 239                            */
 240                           goto trace;
 241                         }
 242
 243                       if ((ether_type0 ==
 244                            clib_net_to_host_u16 (ETHERNET_TYPE_IP6))
 245                           || (ether_type0 ==
 246                               clib_net_to_host_u16 (ETHERNET_TYPE_IP4)))
 247                         {
 248                           is_ip60 =
 249                             (ether_type0 ==
 250                              clib_net_to_host_u16 (ETHERNET_TYPE_IP6)) ? 1 :
 251                             0;
 252                           /*
 253                            * tests against the ACL
 254                            */
 255                           acl_plugin_fill_5tuple_inline (gm->
 256                                                          acl_plugin.p_acl_main,
 257                                                          gc0->gc_lc_index, b0,
 258                                                          is_ip60,
 259                                                          /* is_input */ 0,
 260                                                          /* is_l2_path */ 1,
 261                                                          &pkt_5tuple0);
 262                           acl_plugin_match_5tuple_inline (gm->
 263                                                           acl_plugin.p_acl_main,
 264                                                           gc0->gc_lc_index,
 265                                                           &pkt_5tuple0,
 266                                                           is_ip60, &action0,
 267                                                           &acl_pos_p0,
 268                                                           &acl_match_p0,
 269                                                           &rule_match_p0,
 270                                                           &trace_bitmap0);
 271
 272                           if (action0 > 0)
 273                             {
 274                               vnet_buffer2 (b0)->gbp.flags |=
 275                                 VXLAN_GBP_GPFLAGS_A;
 276                               gu =
 277                                 gbp_rule_get (gc0->gc_rules[rule_match_p0]);
 278
 279                               switch (gu->gu_action)
 280                                 {
 281                                 case GBP_RULE_PERMIT:
 282                                   next0 = vnet_l2_feature_next
 283                                     (b0,
 284                                      gpm->l2_output_feat_next
 285                                      [is_port_based],
 286                                      (is_port_based ?
 287                                       L2OUTPUT_FEAT_GBP_POLICY_PORT :
 288                                       L2OUTPUT_FEAT_GBP_POLICY_MAC));
 289                                   break;
 290                                 case GBP_RULE_DENY:
 291                                   ASSERT (0);
 292                                   next0 = 0;
 293                                   break;
 294                                 case GBP_RULE_REDIRECT:
 295                                   next0 = gbp_rule_l2_redirect (gu, b0);
 296                                   break;
 297                                 }
 298                             }
 299                         }
 300                     }
 301                 }
 302             }
 303           else
 304             {
 305               /*
 306                * the src EPG is not set when the packet arrives on an EPG
 307                * uplink interface and we do not need to apply policy
 308                */
 309               next0 =
 310                 vnet_l2_feature_next (b0,
 311                                       gpm->l2_output_feat_next[is_port_based],
 312                                       (is_port_based ?
 313                                        L2OUTPUT_FEAT_GBP_POLICY_PORT :
 314                                        L2OUTPUT_FEAT_GBP_POLICY_MAC));
 315             }
 316
 317         trace:
 318           if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
 319             {
 320               gbp_policy_trace_t *t =
 321                 vlib_add_trace (vm, node, b0, sizeof (*t));
 322               t->src_epg = key0.gck_src;
 323               t->dst_epg = key0.gck_dst;
 324               t->acl_index = (gc0 ? gc0->gc_acl_index : ~0),
 325                 t->allowed = (next0 != GBP_POLICY_NEXT_DENY);
 326             }
 327
 328           /* verify speculative enqueue, maybe switch current next frame */
 329           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 330                                            to_next, n_left_to_next,
 331                                            bi0, next0);
 332         }
 333
 334       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 335     }
 336
 337   return frame->n_vectors;
 338 }
 339
 340 static uword
 341 gbp_policy_port (vlib_main_t * vm,
 342                  vlib_node_runtime_t * node, vlib_frame_t * frame)
 343 {
 344   return (gbp_policy_inline (vm, node, frame, 1));
 345 }
 346
 347 static uword
 348 gbp_policy_mac (vlib_main_t * vm,
 349                 vlib_node_runtime_t * node, vlib_frame_t * frame)
 350 {
 351   return (gbp_policy_inline (vm, node, frame, 0));
 352 }
 353
 354 /* packet trace format function */
 355 static u8 *
 356 format_gbp_policy_trace (u8 * s, va_list * args)
 357 {
 358   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 359   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 360   gbp_policy_trace_t *t = va_arg (*args, gbp_policy_trace_t *);
 361
 362   s =
 363     format (s, "src:%d, dst:%d, acl:%d allowed:%d",
 364             t->src_epg, t->dst_epg, t->acl_index, t->allowed);
 365
 366   return s;
 367 }
 368
 369 /* *INDENT-OFF* */
 370 VLIB_REGISTER_NODE (gbp_policy_port_node) = {
 371   .function = gbp_policy_port,
 372   .name = "gbp-policy-port",
 373   .vector_size = sizeof (u32),
 374   .format_trace = format_gbp_policy_trace,
 375   .type = VLIB_NODE_TYPE_INTERNAL,
 376
 377   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 378   .error_strings = gbp_policy_error_strings,
 379
 380   .n_next_nodes = GBP_POLICY_N_NEXT,
 381
 382   .next_nodes = {
 383     [GBP_POLICY_NEXT_DENY] = "error-drop",
 384   },
 385 };
 386
 387 VLIB_NODE_FUNCTION_MULTIARCH (gbp_policy_port_node, gbp_policy_port);
 388
 389 VLIB_REGISTER_NODE (gbp_policy_mac_node) = {
 390   .function = gbp_policy_mac,
 391   .name = "gbp-policy-mac",
 392   .vector_size = sizeof (u32),
 393   .format_trace = format_gbp_policy_trace,
 394   .type = VLIB_NODE_TYPE_INTERNAL,
 395   .sibling_of = "gbp-policy-port",
 396 };
 397
 398 VLIB_NODE_FUNCTION_MULTIARCH (gbp_policy_mac_node, gbp_policy_mac);
 399
 400 /* *INDENT-ON* */
 401
 402 static clib_error_t *
 403 gbp_policy_init (vlib_main_t * vm)
 404 {
 405   gbp_policy_main_t *gpm = &gbp_policy_main;
 406   clib_error_t *error = 0;
 407
 408   /* Initialize the feature next-node indexes */
 409   feat_bitmap_init_next_nodes (vm,
 410                                gbp_policy_port_node.index,
 411                                L2OUTPUT_N_FEAT,
 412                                l2output_get_feat_names (),
 413                                gpm->l2_output_feat_next[1]);
 414   feat_bitmap_init_next_nodes (vm,
 415                                gbp_policy_mac_node.index,
 416                                L2OUTPUT_N_FEAT,
 417                                l2output_get_feat_names (),
 418                                gpm->l2_output_feat_next[0]);
 419
 420   return error;
 421 }
 422
 423 VLIB_INIT_FUNCTION (gbp_policy_init);
 424
 425 /*
 426  * fd.io coding-style-patch-verification: ON
 427  *
 428  * Local Variables:
 429  * eval: (c-set-style "gnu")
 430  * End:
 431  */