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
  21 #define foreach_gbp_policy                      \
  22   _(DENY,    "deny")
  23
  24 typedef enum
  25 {
  26 #define _(sym,str) GBP_ERROR_##sym,
  27   foreach_gbp_policy
  28 #undef _
  29     GBP_POLICY_N_ERROR,
  30 } gbp_policy_error_t;
  31
  32 static char *gbp_policy_error_strings[] = {
  33 #define _(sym,string) string,
  34   foreach_gbp_policy
  35 #undef _
  36 };
  37
  38 typedef enum
  39 {
  40 #define _(sym,str) GBP_POLICY_NEXT_##sym,
  41   foreach_gbp_policy
  42 #undef _
  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 } gbp_policy_trace_t;
  57
  58 always_inline dpo_proto_t
  59 ethertype_to_dpo_proto (u16 etype)
  60 {
  61   etype = clib_net_to_host_u16 (etype);
  62
  63   switch (etype)
  64     {
  65     case ETHERNET_TYPE_IP4:
  66       return (DPO_PROTO_IP4);
  67     case ETHERNET_TYPE_IP6:
  68       return (DPO_PROTO_IP6);
  69     }
  70
  71   return (DPO_PROTO_NONE);
  72 }
  73
  74 always_inline u32
  75 gbp_rule_l2_redirect (const gbp_rule_t * gu, vlib_buffer_t * b0)
  76 {
  77   const ethernet_header_t *eth0;
  78   const dpo_id_t *dpo;
  79   dpo_proto_t dproto;
  80
  81   eth0 = vlib_buffer_get_current (b0);
  82   /* pop the ethernet header to prepare for L3 rewrite */
  83   vlib_buffer_advance (b0, vnet_buffer (b0)->l2.l2_len);
  84
  85   dproto = ethertype_to_dpo_proto (eth0->type);
  86   dpo = &gu->gu_dpo[GBP_POLICY_NODE_L2][dproto];
  87
  88   /* save the LB index for the next node and reset the IP flow hash
  89    * so it's recalculated */
  90   vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo->dpoi_index;
  91   vnet_buffer (b0)->ip.flow_hash = 0;
  92
  93   return (dpo->dpoi_next_node);
  94 }
  95
  96 always_inline u8
  97 gbp_policy_is_ethertype_allowed (const gbp_contract_t * gc0, u16 ethertype)
  98 {
  99   u16 *et;
 100
 101   vec_foreach (et, gc0->gc_allowed_ethertypes)
 102   {
 103     if (*et == ethertype)
 104       return (1);
 105   }
 106   return (0);
 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           const gbp_contract_t *gc0;
 134           gbp_policy_next_t next0;
 135           gbp_contract_key_t key0;
 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_sclass;
 179           else
 180             /* If you cannot determine the destination EP then drop */
 181             goto trace;
 182
 183           key0.gck_src = vnet_buffer2 (b0)->gbp.sclass;
 184
 185           if (SCLASS_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                       u32 rule_match_p0, trace_bitmap0;
 208                       fa_5tuple_opaque_t pkt_5tuple0;
 209                       u32 acl_pos_p0, acl_match_p0;
 210                       u8 is_ip60, l2_len0, action0;
 211                       const gbp_rule_t *gu;
 212                       u16 ether_type0;
 213                       const u8 *h0;
 214
 215                       action0 = 0;
 216                       gc0 = gbp_contract_get (gci0);
 217                       l2_len0 = vnet_buffer (b0)->l2.l2_len;
 218                       h0 = vlib_buffer_get_current (b0);
 219
 220                       ether_type0 = *(u16 *) (h0 + l2_len0 - 2);
 221
 222                       if (!gbp_policy_is_ethertype_allowed (gc0, ether_type0))
 223                         {
 224                           /*
 225                            * black list model so drop
 226                            */
 227                           goto trace;
 228                         }
 229
 230                       if ((ether_type0 ==
 231                            clib_net_to_host_u16 (ETHERNET_TYPE_IP6))
 232                           || (ether_type0 ==
 233                               clib_net_to_host_u16 (ETHERNET_TYPE_IP4)))
 234                         {
 235                           is_ip60 =
 236                             (ether_type0 ==
 237                              clib_net_to_host_u16 (ETHERNET_TYPE_IP6)) ? 1 :
 238                             0;
 239                           /*
 240                            * tests against the ACL
 241                            */
 242                           acl_plugin_fill_5tuple_inline (gm->
 243                                                          acl_plugin.p_acl_main,
 244                                                          gc0->gc_lc_index, b0,
 245                                                          is_ip60,
 246                                                          /* is_input */ 0,
 247                                                          /* is_l2_path */ 1,
 248                                                          &pkt_5tuple0);
 249                           acl_plugin_match_5tuple_inline (gm->
 250                                                           acl_plugin.p_acl_main,
 251                                                           gc0->gc_lc_index,
 252                                                           &pkt_5tuple0,
 253                                                           is_ip60, &action0,
 254                                                           &acl_pos_p0,
 255                                                           &acl_match_p0,
 256                                                           &rule_match_p0,
 257                                                           &trace_bitmap0);
 258
 259                           if (action0 > 0)
 260                             {
 261                               vnet_buffer2 (b0)->gbp.flags |=
 262                                 VXLAN_GBP_GPFLAGS_A;
 263                               gu =
 264                                 gbp_rule_get (gc0->gc_rules[rule_match_p0]);
 265
 266                               switch (gu->gu_action)
 267                                 {
 268                                 case GBP_RULE_PERMIT:
 269                                   next0 = vnet_l2_feature_next
 270                                     (b0,
 271                                      gpm->l2_output_feat_next
 272                                      [is_port_based],
 273                                      (is_port_based ?
 274                                       L2OUTPUT_FEAT_GBP_POLICY_PORT :
 275                                       L2OUTPUT_FEAT_GBP_POLICY_MAC));
 276                                   break;
 277                                 case GBP_RULE_DENY:
 278                                   next0 = 0;
 279                                   break;
 280                                 case GBP_RULE_REDIRECT:
 281                                   next0 = gbp_rule_l2_redirect (gu, b0);
 282                                   break;
 283                                 }
 284                             }
 285                         }
 286                     }
 287                 }
 288             }
 289           else
 290             {
 291               /*
 292                * the src EPG is not set when the packet arrives on an EPG
 293                * uplink interface and we do not need to apply policy
 294                */
 295               next0 =
 296                 vnet_l2_feature_next (b0,
 297                                       gpm->l2_output_feat_next[is_port_based],
 298                                       (is_port_based ?
 299                                        L2OUTPUT_FEAT_GBP_POLICY_PORT :
 300                                        L2OUTPUT_FEAT_GBP_POLICY_MAC));
 301             }
 302
 303         trace:
 304           if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
 305             {
 306               gbp_policy_trace_t *t =
 307                 vlib_add_trace (vm, node, b0, sizeof (*t));
 308               t->sclass = key0.gck_src;
 309               t->dst_epg = key0.gck_dst;
 310               t->acl_index = (gc0 ? gc0->gc_acl_index : ~0),
 311                 t->allowed = (next0 != GBP_POLICY_NEXT_DENY);
 312             }
 313
 314           /* verify speculative enqueue, maybe switch current next frame */
 315           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 316                                            to_next, n_left_to_next,
 317                                            bi0, next0);
 318         }
 319
 320       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 321     }
 322
 323   return frame->n_vectors;
 324 }
 325
 326 VLIB_NODE_FN (gbp_policy_port_node) (vlib_main_t * vm,
 327                                      vlib_node_runtime_t * node,
 328                                      vlib_frame_t * frame)
 329 {
 330   return (gbp_policy_inline (vm, node, frame, 1));
 331 }
 332
 333 VLIB_NODE_FN (gbp_policy_mac_node) (vlib_main_t * vm,
 334                                     vlib_node_runtime_t * node,
 335                                     vlib_frame_t * frame)
 336 {
 337   return (gbp_policy_inline (vm, node, frame, 0));
 338 }
 339
 340 /* packet trace format function */
 341 static u8 *
 342 format_gbp_policy_trace (u8 * s, va_list * args)
 343 {
 344   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 345   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 346   gbp_policy_trace_t *t = va_arg (*args, gbp_policy_trace_t *);
 347
 348   s =
 349     format (s, "sclass:%d, dst:%d, acl:%d allowed:%d",
 350             t->sclass, t->dst_epg, t->acl_index, t->allowed);
 351
 352   return s;
 353 }
 354
 355 /* *INDENT-OFF* */
 356 VLIB_REGISTER_NODE (gbp_policy_port_node) = {
 357   .name = "gbp-policy-port",
 358   .vector_size = sizeof (u32),
 359   .format_trace = format_gbp_policy_trace,
 360   .type = VLIB_NODE_TYPE_INTERNAL,
 361
 362   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 363   .error_strings = gbp_policy_error_strings,
 364
 365   .n_next_nodes = GBP_POLICY_N_NEXT,
 366
 367   .next_nodes = {
 368     [GBP_POLICY_NEXT_DENY] = "error-drop",
 369   },
 370 };
 371
 372 VLIB_REGISTER_NODE (gbp_policy_mac_node) = {
 373   .name = "gbp-policy-mac",
 374   .vector_size = sizeof (u32),
 375   .format_trace = format_gbp_policy_trace,
 376   .type = VLIB_NODE_TYPE_INTERNAL,
 377   .sibling_of = "gbp-policy-port",
 378 };
 379
 380 /* *INDENT-ON* */
 381
 382 /*
 383  * fd.io coding-style-patch-verification: ON
 384  *
 385  * Local Variables:
 386  * eval: (c-set-style "gnu")
 387  * End:
 388  */