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 static uword
 110 gbp_policy_inline (vlib_main_t * vm,
 111                    vlib_node_runtime_t * node,
 112                    vlib_frame_t * frame, u8 is_port_based)
 113 {
 114   gbp_main_t *gm = &gbp_main;
 115   gbp_policy_main_t *gpm = &gbp_policy_main;
 116   u32 n_left_from, *from, *to_next;
 117   u32 next_index;
 118
 119   next_index = 0;
 120   n_left_from = frame->n_vectors;
 121   from = vlib_frame_vector_args (frame);
 122
 123   while (n_left_from > 0)
 124     {
 125       u32 n_left_to_next;
 126
 127       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 128
 129       while (n_left_from > 0 && n_left_to_next > 0)
 130         {
 131           const ethernet_header_t *h0;
 132           const gbp_endpoint_t *ge0;
 133           gbp_policy_next_t next0;
 134           gbp_contract_key_t key0;
 135           gbp_contract_t *gc0;
 136           u32 bi0, sw_if_index0;
 137           vlib_buffer_t *b0;
 138           index_t gci0;
 139
 140           gc0 = NULL;
 141           next0 = GBP_POLICY_NEXT_DENY;
 142           bi0 = from[0];
 143           to_next[0] = bi0;
 144           from += 1;
 145           to_next += 1;
 146           n_left_from -= 1;
 147           n_left_to_next -= 1;
 148
 149           b0 = vlib_get_buffer (vm, bi0);
 150           h0 = vlib_buffer_get_current (b0);
 151           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 152
 153           /*
 154            * If the A0bit is set then policy has already been applied
 155            * and we skip enforcement here.
 156            */
 157           if (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_A)
 158             {
 159               next0 = vnet_l2_feature_next (b0,
 160                                             gpm->l2_output_feat_next
 161                                             [is_port_based],
 162                                             (is_port_based ?
 163                                              L2OUTPUT_FEAT_GBP_POLICY_PORT :
 164                                              L2OUTPUT_FEAT_GBP_POLICY_MAC));
 165               key0.as_u32 = ~0;
 166               goto trace;
 167             }
 168           /*
 169            * determine the src and dst EPG
 170            */
 171           if (is_port_based)
 172             ge0 = gbp_endpoint_find_itf (sw_if_index0);
 173           else
 174             ge0 = gbp_endpoint_find_mac (h0->dst_address,
 175                                          vnet_buffer (b0)->l2.bd_index);
 176
 177           if (NULL != ge0)
 178             key0.gck_dst = ge0->ge_fwd.gef_epg_id;
 179           else
 180             /* If you cannot determine the destination EP then drop */
 181             goto trace;
 182
 183           key0.gck_src = vnet_buffer2 (b0)->gbp.src_epg;
 184
 185           if (EPG_INVALID != key0.gck_src)
 186             {
 187               if (PREDICT_FALSE (key0.gck_src == key0.gck_dst))
 188                 {
 189                   /*
 190                    * intra-epg allowed
 191                    */
 192                   next0 =
 193                     vnet_l2_feature_next (b0,
 194                                           gpm->l2_output_feat_next
 195                                           [is_port_based],
 196                                           (is_port_based ?
 197                                            L2OUTPUT_FEAT_GBP_POLICY_PORT :
 198                                            L2OUTPUT_FEAT_GBP_POLICY_MAC));
 199                   vnet_buffer2 (b0)->gbp.flags |= VXLAN_GBP_GPFLAGS_A;
 200                 }
 201               else
 202                 {
 203                   gci0 = gbp_contract_find (&key0);
 204
 205                   if (INDEX_INVALID != gci0)
 206                     {
 207                       fa_5tuple_opaque_t pkt_5tuple0;
 208                       u8 action0 = 0;
 209                       u32 acl_pos_p0, acl_match_p0;
 210                       u32 rule_match_p0, trace_bitmap0;
 211                       u8 *h0, l2_len0;
 212                       u16 ether_type0;
 213                       u8 is_ip60 = 0;
 214
 215                       gc0 = gbp_contract_get (gci0);
 216                       l2_len0 = vnet_buffer (b0)->l2.l2_len;
 217                       h0 = vlib_buffer_get_current (b0);
 218
 219                       ether_type0 =
 220                         clib_net_to_host_u16 (*(u16 *) (h0 + l2_len0 - 2));
 221
 222                       is_ip60 = (ether_type0 == ETHERNET_TYPE_IP6) ? 1 : 0;
 223                       /*
 224                        * tests against the ACL
 225                        */
 226                       acl_plugin_fill_5tuple_inline (gm->
 227                                                      acl_plugin.p_acl_main,
 228                                                      gc0->gc_lc_index, b0,
 229                                                      is_ip60,
 230                                                      /* is_input */ 0,
 231                                                      /* is_l2_path */ 1,
 232                                                      &pkt_5tuple0);
 233                       acl_plugin_match_5tuple_inline (gm->
 234                                                       acl_plugin.p_acl_main,
 235                                                       gc0->gc_lc_index,
 236                                                       &pkt_5tuple0, is_ip60,
 237                                                       &action0, &acl_pos_p0,
 238                                                       &acl_match_p0,
 239                                                       &rule_match_p0,
 240                                                       &trace_bitmap0);
 241
 242                       if (action0 > 0)
 243                         {
 244                           gbp_rule_t *gu;
 245
 246                           vnet_buffer2 (b0)->gbp.flags |= VXLAN_GBP_GPFLAGS_A;
 247                           gu = gbp_rule_get (gc0->gc_rules[rule_match_p0]);
 248
 249                           switch (gu->gu_action)
 250                             {
 251                             case GBP_RULE_PERMIT:
 252                               next0 = vnet_l2_feature_next
 253                                 (b0,
 254                                  gpm->l2_output_feat_next
 255                                  [is_port_based],
 256                                  (is_port_based ?
 257                                   L2OUTPUT_FEAT_GBP_POLICY_PORT :
 258                                   L2OUTPUT_FEAT_GBP_POLICY_MAC));
 259                               break;
 260                             case GBP_RULE_DENY:
 261                               ASSERT (0);
 262                               next0 = 0;
 263                               break;
 264                             case GBP_RULE_REDIRECT:
 265                               next0 = gbp_rule_l2_redirect (gu, b0);
 266                               break;
 267                             }
 268                         }
 269                     }
 270                 }
 271             }
 272           else
 273             {
 274               /*
 275                * the src EPG is not set when the packet arrives on an EPG
 276                * uplink interface and we do not need to apply policy
 277                */
 278               next0 =
 279                 vnet_l2_feature_next (b0,
 280                                       gpm->l2_output_feat_next[is_port_based],
 281                                       (is_port_based ?
 282                                        L2OUTPUT_FEAT_GBP_POLICY_PORT :
 283                                        L2OUTPUT_FEAT_GBP_POLICY_MAC));
 284             }
 285
 286         trace:
 287           if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
 288             {
 289               gbp_policy_trace_t *t =
 290                 vlib_add_trace (vm, node, b0, sizeof (*t));
 291               t->src_epg = key0.gck_src;
 292               t->dst_epg = key0.gck_dst;
 293               t->acl_index = (gc0 ? gc0->gc_acl_index : ~0),
 294                 t->allowed = (next0 != GBP_POLICY_NEXT_DENY);
 295             }
 296
 297           /* verify speculative enqueue, maybe switch current next frame */
 298           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 299                                            to_next, n_left_to_next,
 300                                            bi0, next0);
 301         }
 302
 303       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 304     }
 305
 306   return frame->n_vectors;
 307 }
 308
 309 static uword
 310 gbp_policy_port (vlib_main_t * vm,
 311                  vlib_node_runtime_t * node, vlib_frame_t * frame)
 312 {
 313   return (gbp_policy_inline (vm, node, frame, 1));
 314 }
 315
 316 static uword
 317 gbp_policy_mac (vlib_main_t * vm,
 318                 vlib_node_runtime_t * node, vlib_frame_t * frame)
 319 {
 320   return (gbp_policy_inline (vm, node, frame, 0));
 321 }
 322
 323 /* packet trace format function */
 324 static u8 *
 325 format_gbp_policy_trace (u8 * s, va_list * args)
 326 {
 327   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 328   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 329   gbp_policy_trace_t *t = va_arg (*args, gbp_policy_trace_t *);
 330
 331   s =
 332     format (s, "src:%d, dst:%d, acl:%d allowed:%d",
 333             t->src_epg, t->dst_epg, t->acl_index, t->allowed);
 334
 335   return s;
 336 }
 337
 338 /* *INDENT-OFF* */
 339 VLIB_REGISTER_NODE (gbp_policy_port_node) = {
 340   .function = gbp_policy_port,
 341   .name = "gbp-policy-port",
 342   .vector_size = sizeof (u32),
 343   .format_trace = format_gbp_policy_trace,
 344   .type = VLIB_NODE_TYPE_INTERNAL,
 345
 346   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 347   .error_strings = gbp_policy_error_strings,
 348
 349   .n_next_nodes = GBP_POLICY_N_NEXT,
 350
 351   .next_nodes = {
 352     [GBP_POLICY_NEXT_DENY] = "error-drop",
 353   },
 354 };
 355
 356 VLIB_NODE_FUNCTION_MULTIARCH (gbp_policy_port_node, gbp_policy_port);
 357
 358 VLIB_REGISTER_NODE (gbp_policy_mac_node) = {
 359   .function = gbp_policy_mac,
 360   .name = "gbp-policy-mac",
 361   .vector_size = sizeof (u32),
 362   .format_trace = format_gbp_policy_trace,
 363   .type = VLIB_NODE_TYPE_INTERNAL,
 364   .sibling_of = "gbp-policy-port",
 365 };
 366
 367 VLIB_NODE_FUNCTION_MULTIARCH (gbp_policy_mac_node, gbp_policy_mac);
 368
 369 /* *INDENT-ON* */
 370
 371 static clib_error_t *
 372 gbp_policy_init (vlib_main_t * vm)
 373 {
 374   gbp_policy_main_t *gpm = &gbp_policy_main;
 375   clib_error_t *error = 0;
 376
 377   /* Initialize the feature next-node indexes */
 378   feat_bitmap_init_next_nodes (vm,
 379                                gbp_policy_port_node.index,
 380                                L2OUTPUT_N_FEAT,
 381                                l2output_get_feat_names (),
 382                                gpm->l2_output_feat_next[1]);
 383   feat_bitmap_init_next_nodes (vm,
 384                                gbp_policy_mac_node.index,
 385                                L2OUTPUT_N_FEAT,
 386                                l2output_get_feat_names (),
 387                                gpm->l2_output_feat_next[0]);
 388
 389   return error;
 390 }
 391
 392 VLIB_INIT_FUNCTION (gbp_policy_init);
 393
 394 /*
 395  * fd.io coding-style-patch-verification: ON
 396  *
 397  * Local Variables:
 398  * eval: (c-set-style "gnu")
 399  * End:
 400  */