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