src/plugins/nat/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.h>
  16 #include <nat/nat_inlines.h>
  17
  18 vlib_node_registration_t dslite_ce_decap_node;
  19
  20 typedef enum
  21 {
  22   DSLITE_CE_DECAP_NEXT_IP4_LOOKUP,
  23   DSLITE_IN2OUT_NEXT_IP6_ICMP,
  24   DSLITE_CE_DECAP_NEXT_DROP,
  25   DSLITE_CE_DECAP_N_NEXT,
  26 } dslite_ce_decap_next_t;
  27
  28 static char *dslite_ce_decap_error_strings[] = {
  29 #define _(sym,string) string,
  30   foreach_dslite_error
  31 #undef _
  32 };
  33
  34 static uword
  35 dslite_ce_decap_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
  36                          vlib_frame_t * frame)
  37 {
  38   u32 n_left_from, *from, *to_next;
  39   dslite_ce_decap_next_t next_index;
  40
  41   from = vlib_frame_vector_args (frame);
  42   n_left_from = frame->n_vectors;
  43   next_index = node->cached_next_index;
  44
  45   while (n_left_from > 0)
  46     {
  47       u32 n_left_to_next;
  48
  49       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  50
  51       while (n_left_from > 0 && n_left_to_next > 0)
  52         {
  53           u32 bi0;
  54           vlib_buffer_t *b0;
  55           u32 next0 = DSLITE_CE_DECAP_NEXT_IP4_LOOKUP;
  56           u8 error0 = DSLITE_ERROR_CE_DECAP;
  57           ip4_header_t *ip40;
  58           ip6_header_t *ip60;
  59           u32 proto0;
  60
  61           /* speculatively enqueue b0 to the current next frame */
  62           bi0 = from[0];
  63           to_next[0] = bi0;
  64           from += 1;
  65           to_next += 1;
  66           n_left_from -= 1;
  67           n_left_to_next -= 1;
  68
  69           b0 = vlib_get_buffer (vm, bi0);
  70           ip60 = vlib_buffer_get_current (b0);
  71
  72           if (PREDICT_FALSE (ip60->protocol != IP_PROTOCOL_IP_IN_IP))
  73             {
  74               if (ip60->protocol == IP_PROTOCOL_ICMP6)
  75                 {
  76                   next0 = DSLITE_IN2OUT_NEXT_IP6_ICMP;
  77                   goto trace0;
  78                 }
  79               error0 = DSLITE_ERROR_BAD_IP6_PROTOCOL;
  80               next0 = DSLITE_CE_DECAP_NEXT_DROP;
  81               goto trace0;
  82             }
  83
  84           ip40 = vlib_buffer_get_current (b0) + sizeof (ip6_header_t);
  85           proto0 = ip_proto_to_snat_proto (ip40->protocol);
  86
  87           if (PREDICT_FALSE (proto0 == ~0))
  88             {
  89               error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
  90               next0 = DSLITE_CE_DECAP_NEXT_DROP;
  91               goto trace0;
  92             }
  93
  94           ip40->tos =
  95             (clib_net_to_host_u32
  96              (ip60->ip_version_traffic_class_and_flow_label) & 0x0ff00000) >>
  97             20;
  98           vlib_buffer_advance (b0, sizeof (ip6_header_t));
  99
 100         trace0:
 101           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 102                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 103             {
 104               dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
 105               t->next_index = next0;
 106             }
 107
 108           b0->error = node->errors[error0];
 109
 110           /* verify speculative enqueue, maybe switch current next frame */
 111           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 112                                            n_left_to_next, bi0, next0);
 113         }
 114       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 115     }
 116
 117   return frame->n_vectors;
 118 }
 119
 120 /* *INDENT-OFF* */
 121 VLIB_REGISTER_NODE (dslite_ce_decap_node) = {
 122   .function = dslite_ce_decap_node_fn,
 123   .name = "dslite-ce-decap",
 124   .vector_size = sizeof (u32),
 125   .format_trace = format_dslite_ce_trace,
 126   .type = VLIB_NODE_TYPE_INTERNAL,
 127   .n_errors = ARRAY_LEN (dslite_ce_decap_error_strings),
 128   .error_strings = dslite_ce_decap_error_strings,
 129   .n_next_nodes = DSLITE_CE_DECAP_N_NEXT,
 130   /* edit / add dispositions here */
 131   .next_nodes = {
 132     [DSLITE_CE_DECAP_NEXT_DROP] = "error-drop",
 133     [DSLITE_CE_DECAP_NEXT_IP4_LOOKUP] = "ip4-lookup",
 134     [DSLITE_IN2OUT_NEXT_IP6_ICMP] = "ip6-icmp-input",
 135   },
 136 };
 137 /* *INDENT-ON* */
 138
 139 VLIB_NODE_FUNCTION_MULTIARCH (dslite_ce_decap_node, dslite_ce_decap_node_fn);
 140
 141 /*
 142  * fd.io coding-style-patch-verification: ON
 143  *
 144  * Local Variables:
 145  * eval: (c-set-style "gnu")
 146  * End:
 147  */