src/plugins/nat/dslite/dslite_ce_decap.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 #include <nat/dslite/dslite.h>
  16 #include <nat/nat_inlines.h>
  17
  18 typedef enum
  19 {
  20   DSLITE_CE_DECAP_NEXT_IP4_LOOKUP,
  21   DSLITE_IN2OUT_NEXT_IP6_ICMP,
  22   DSLITE_CE_DECAP_NEXT_DROP,
  23   DSLITE_CE_DECAP_N_NEXT,
  24 } dslite_ce_decap_next_t;
  25
  26 static char *dslite_ce_decap_error_strings[] = {
  27 #define _(sym,string) string,
  28   foreach_dslite_error
  29 #undef _
  30 };
  31
  32 VLIB_NODE_FN (dslite_ce_decap_node) (vlib_main_t * vm,
  33                                      vlib_node_runtime_t * node,
  34                                      vlib_frame_t * frame)
  35 {
  36   u32 n_left_from, *from, *to_next;
  37   dslite_ce_decap_next_t next_index;
  38
  39   from = vlib_frame_vector_args (frame);
  40   n_left_from = frame->n_vectors;
  41   next_index = node->cached_next_index;
  42
  43   while (n_left_from > 0)
  44     {
  45       u32 n_left_to_next;
  46
  47       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  48
  49       while (n_left_from > 0 && n_left_to_next > 0)
  50         {
  51           u32 bi0;
  52           vlib_buffer_t *b0;
  53           u32 next0 = DSLITE_CE_DECAP_NEXT_IP4_LOOKUP;
  54           u8 error0 = DSLITE_ERROR_CE_DECAP;
  55           ip4_header_t *ip40;
  56           ip6_header_t *ip60;
  57           u32 proto0;
  58
  59           /* speculatively enqueue b0 to the current next frame */
  60           bi0 = from[0];
  61           to_next[0] = bi0;
  62           from += 1;
  63           to_next += 1;
  64           n_left_from -= 1;
  65           n_left_to_next -= 1;
  66
  67           b0 = vlib_get_buffer (vm, bi0);
  68           ip60 = vlib_buffer_get_current (b0);
  69
  70           if (PREDICT_FALSE (ip60->protocol != IP_PROTOCOL_IP_IN_IP))
  71             {
  72               if (ip60->protocol == IP_PROTOCOL_ICMP6)
  73                 {
  74                   next0 = DSLITE_IN2OUT_NEXT_IP6_ICMP;
  75                   goto trace0;
  76                 }
  77               error0 = DSLITE_ERROR_BAD_IP6_PROTOCOL;
  78               next0 = DSLITE_CE_DECAP_NEXT_DROP;
  79               goto trace0;
  80             }
  81
  82           ip40 = vlib_buffer_get_current (b0) + sizeof (ip6_header_t);
  83           proto0 = ip_proto_to_snat_proto (ip40->protocol);
  84
  85           if (PREDICT_FALSE (proto0 == ~0))
  86             {
  87               error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
  88               next0 = DSLITE_CE_DECAP_NEXT_DROP;
  89               goto trace0;
  90             }
  91
  92           ip40->tos =
  93             (clib_net_to_host_u32
  94              (ip60->ip_version_traffic_class_and_flow_label) & 0x0ff00000) >>
  95             20;
  96           vlib_buffer_advance (b0, sizeof (ip6_header_t));
  97
  98         trace0:
  99           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 100                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 101             {
 102               dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
 103               t->next_index = next0;
 104             }
 105
 106           b0->error = node->errors[error0];
 107
 108           /* verify speculative enqueue, maybe switch current next frame */
 109           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 110                                            n_left_to_next, bi0, next0);
 111         }
 112       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 113     }
 114
 115   return frame->n_vectors;
 116 }
 117
 118 /* *INDENT-OFF* */
 119 VLIB_REGISTER_NODE (dslite_ce_decap_node) = {
 120   .name = "dslite-ce-decap",
 121   .vector_size = sizeof (u32),
 122   .format_trace = format_dslite_ce_trace,
 123   .type = VLIB_NODE_TYPE_INTERNAL,
 124   .n_errors = ARRAY_LEN (dslite_ce_decap_error_strings),
 125   .error_strings = dslite_ce_decap_error_strings,
 126   .n_next_nodes = DSLITE_CE_DECAP_N_NEXT,
 127   /* edit / add dispositions here */
 128   .next_nodes = {
 129     [DSLITE_CE_DECAP_NEXT_DROP] = "error-drop",
 130     [DSLITE_CE_DECAP_NEXT_IP4_LOOKUP] = "ip4-lookup",
 131     [DSLITE_IN2OUT_NEXT_IP6_ICMP] = "ip6-icmp-input",
 132   },
 133 };
 134 /* *INDENT-ON* */
 135
 136 /*
 137  * fd.io coding-style-patch-verification: ON
 138  *
 139  * Local Variables:
 140  * eval: (c-set-style "gnu")
 141  * End:
 142  */