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_ERROR_##sym,
  29   foreach_gbp_policy
  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
  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;
 119
 120   next_index = 0;
 121   n_left_from = frame->n_vectors;
 122   from = vlib_frame_vector_args (frame);
 123
 124   while (n_left_from > 0)
 125     {
 126       u32 n_left_to_next;
 127
 128       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 129
 130       while (n_left_from > 0 && n_left_to_next > 0)
 131         {
 132           const ethernet_header_t *h0;
 133           const gbp_endpoint_t *ge0;
 134           const gbp_contract_t *gc0;
 135           gbp_policy_next_t next0;
 136           gbp_contract_key_t key0;
 137           u32 bi0, sw_if_index0;
 138           vlib_buffer_t *b0;
 139           index_t gci0;
 140
 141           gc0 = NULL;
 142           next0 = GBP_POLICY_NEXT_DROP;
 143           bi0 = from[0];
 144           to_next[0] = bi0;
 145           from += 1;
 146           to_next += 1;
 147           n_left_from -= 1;
 148           n_left_to_next -= 1;
 149
 150           b0 = vlib_get_buffer (vm, bi0);
 151           h0 = vlib_buffer_get_current (b0);
 152           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
 153
 154           /*
 155            * Reflection check; in and out on an ivxlan tunnel
 156            */
 157           if ((~0 != vxlan_gbp_tunnel_by_sw_if_index (sw_if_index0)) &&
 158               (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_R))
 159             {
 160               goto trace;
 161             }
 162
 163           /*
 164            * If the A-bit is set then policy has already been applied
 165            * and we skip enforcement here.
 166            */
 167           if (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_A)
 168             {
 169               next0 = vnet_l2_feature_next (b0,
 170                                             gpm->l2_output_feat_next
 171                                             [is_port_based],
 172                                             (is_port_based ?
 173                                              L2OUTPUT_FEAT_GBP_POLICY_PORT :
 174                                              L2OUTPUT_FEAT_GBP_POLICY_MAC));
 175               key0.as_u32 = ~0;
 176               goto trace;
 177             }
 178
 179           /*
 180            * determine the src and dst EPG
 181            */
 182           if (is_port_based)
 183             ge0 = gbp_endpoint_find_itf (sw_if_index0);
 184           else
 185             ge0 = gbp_endpoint_find_mac (h0->dst_address,
 186                                          vnet_buffer (b0)->l2.bd_index);
 187
 188           if (NULL != ge0)
 189             key0.gck_dst = ge0->ge_fwd.gef_sclass;
 190           else
 191             /* If you cannot determine the destination EP then drop */
 192             goto trace;
 193
 194           key0.gck_src = vnet_buffer2 (b0)->gbp.sclass;
 195
 196           if (SCLASS_INVALID != key0.gck_src)
 197             {
 198               if (PREDICT_FALSE (key0.gck_src == key0.gck_dst))
 199                 {
 200                   /*
 201                    * intra-epg allowed
 202                    */
 203                   next0 =
 204                     vnet_l2_feature_next (b0,
 205                                           gpm->l2_output_feat_next
 206                                           [is_port_based],
 207                                           (is_port_based ?
 208                                            L2OUTPUT_FEAT_GBP_POLICY_PORT :
 209                                            L2OUTPUT_FEAT_GBP_POLICY_MAC));
 210                   vnet_buffer2 (b0)->gbp.flags |= VXLAN_GBP_GPFLAGS_A;
 211                 }
 212               else
 213                 {
 214                   gci0 = gbp_contract_find (&key0);
 215
 216                   if (INDEX_INVALID != gci0)
 217                     {
 218                       u32 rule_match_p0, trace_bitmap0;
 219                       fa_5tuple_opaque_t pkt_5tuple0;
 220                       u32 acl_pos_p0, acl_match_p0;
 221                       u8 is_ip60, l2_len0, action0;
 222                       const gbp_rule_t *gu;
 223                       u16 ether_type0;
 224                       const u8 *h0;
 225
 226                       action0 = 0;
 227                       gc0 = gbp_contract_get (gci0);
 228                       l2_len0 = vnet_buffer (b0)->l2.l2_len;
 229                       h0 = vlib_buffer_get_current (b0);
 230
 231                       ether_type0 = *(u16 *) (h0 + l2_len0 - 2);
 232
 233                       if (!gbp_policy_is_ethertype_allowed (gc0, ether_type0))
 234                         {
 235                           /*
 236                            * black list model so drop
 237                            */
 238                           goto trace;
 239                         }
 240
 241                       if ((ether_type0 ==
 242                            clib_net_to_host_u16 (ETHERNET_TYPE_IP6))
 243                           || (ether_type0 ==
 244                               clib_net_to_host_u16 (ETHERNET_TYPE_IP4)))
 245                         {
 246                           is_ip60 =
 247                             (ether_type0 ==
 248                              clib_net_to_host_u16 (ETHERNET_TYPE_IP6)) ? 1 :
 249                             0;
 250                           /*
 251                            * tests against the ACL
 252                            */
 253                           acl_plugin_fill_5tuple_inline (gm->
 254                                                          acl_plugin.p_acl_main,
 255                                                          gc0->gc_lc_index, b0,
 256                                                          is_ip60,
 257                                                          /* is_input */ 0,
 258                                                          /* is_l2_path */ 1,
 259                                                          &pkt_5tuple0);
 260                           acl_plugin_match_5tuple_inline (gm->
 261                                                           acl_plugin.p_acl_main,
 262                                                           gc0->gc_lc_index,
 263                                                           &pkt_5tuple0,
 264                                                           is_ip60, &action0,
 265                                                           &acl_pos_p0,
 266                                                           &acl_match_p0,
 267                                                           &rule_match_p0,
 268                                                           &trace_bitmap0);
 269
 270                           if (action0 > 0)
 271                             {
 272                               vnet_buffer2 (b0)->gbp.flags |=
 273                                 VXLAN_GBP_GPFLAGS_A;
 274                               gu =
 275                                 gbp_rule_get (gc0->gc_rules[rule_match_p0]);
 276
 277                               switch (gu->gu_action)
 278                                 {
 279                                 case GBP_RULE_PERMIT:
 280                                   next0 = vnet_l2_feature_next
 281                                     (b0,
 282                                      gpm->l2_output_feat_next
 283                                      [is_port_based],
 284                                      (is_port_based ?
 285                                       L2OUTPUT_FEAT_GBP_POLICY_PORT :
 286                                       L2OUTPUT_FEAT_GBP_POLICY_MAC));
 287                                   break;
 288                                 case GBP_RULE_DENY:
 289                                   next0 = 0;
 290                                   break;
 291                                 case GBP_RULE_REDIRECT:
 292                                   next0 = gbp_rule_l2_redirect (gu, b0);
 293                                   break;
 294                                 }
 295                             }
 296                         }
 297                     }
 298                 }
 299             }
 300           else
 301             {
 302               /*
 303                * the src EPG is not set when the packet arrives on an EPG
 304                * uplink interface and we do not need to apply policy
 305                */
 306               next0 =
 307                 vnet_l2_feature_next (b0,
 308                                       gpm->l2_output_feat_next[is_port_based],
 309                                       (is_port_based ?
 310                                        L2OUTPUT_FEAT_GBP_POLICY_PORT :
 311                                        L2OUTPUT_FEAT_GBP_POLICY_MAC));
 312             }
 313
 314         trace:
 315           if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
 316             {
 317               gbp_policy_trace_t *t =
 318                 vlib_add_trace (vm, node, b0, sizeof (*t));
 319               t->sclass = key0.gck_src;
 320               t->dst_epg = key0.gck_dst;
 321               t->acl_index = (gc0 ? gc0->gc_acl_index : ~0);
 322               t->allowed = (next0 != GBP_POLICY_NEXT_DROP);
 323               t->flags = vnet_buffer2 (b0)->gbp.flags;
 324             }
 325
 326           /* verify speculative enqueue, maybe switch current next frame */
 327           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 328                                            to_next, n_left_to_next,
 329                                            bi0, next0);
 330         }
 331
 332       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 333     }
 334
 335   return frame->n_vectors;
 336 }
 337
 338 VLIB_NODE_FN (gbp_policy_port_node) (vlib_main_t * vm,
 339                                      vlib_node_runtime_t * node,
 340                                      vlib_frame_t * frame)
 341 {
 342   return (gbp_policy_inline (vm, node, frame, 1));
 343 }
 344
 345 VLIB_NODE_FN (gbp_policy_mac_node) (vlib_main_t * vm,
 346                                     vlib_node_runtime_t * node,
 347                                     vlib_frame_t * frame)
 348 {
 349   return (gbp_policy_inline (vm, node, frame, 0));
 350 }
 351
 352 /* packet trace format function */
 353 static u8 *
 354 format_gbp_policy_trace (u8 * s, va_list * args)
 355 {
 356   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 357   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 358   gbp_policy_trace_t *t = va_arg (*args, gbp_policy_trace_t *);
 359
 360   s =
 361     format (s, "sclass:%d, dst:%d, acl:%d allowed:%d flags:%U",
 362             t->sclass, t->dst_epg, t->acl_index, t->allowed,
 363             format_vxlan_gbp_header_gpflags, t->flags);
 364
 365   return s;
 366 }
 367
 368 /* *INDENT-OFF* */
 369 VLIB_REGISTER_NODE (gbp_policy_port_node) = {
 370   .name = "gbp-policy-port",
 371   .vector_size = sizeof (u32),
 372   .format_trace = format_gbp_policy_trace,
 373   .type = VLIB_NODE_TYPE_INTERNAL,
 374
 375   .n_errors = ARRAY_LEN(gbp_policy_error_strings),
 376   .error_strings = gbp_policy_error_strings,
 377
 378   .n_next_nodes = GBP_POLICY_N_NEXT,
 379
 380   .next_nodes = {
 381     [GBP_POLICY_NEXT_DROP] = "error-drop",
 382   },
 383 };
 384
 385 VLIB_REGISTER_NODE (gbp_policy_mac_node) = {
 386   .name = "gbp-policy-mac",
 387   .vector_size = sizeof (u32),
 388   .format_trace = format_gbp_policy_trace,
 389   .type = VLIB_NODE_TYPE_INTERNAL,
 390   .sibling_of = "gbp-policy-port",
 391 };
 392
 393 /* *INDENT-ON* */
 394
 395 /*
 396  * fd.io coding-style-patch-verification: ON
 397  *
 398  * Local Variables:
 399  * eval: (c-set-style "gnu")
 400  * End:
 401  */