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