src/plugins/nat/dslite_ce_encap.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_encap_node;
  18
  19 typedef enum
  20 {
  21   DSLITE_CE_ENCAP_NEXT_IP6_LOOKUP,
  22   DSLITE_CE_ENCAP_NEXT_DROP,
  23   DSLITE_CE_ENCAP_N_NEXT,
  24 } dslite_ce_encap_next_t;
  25
  26 static char *dslite_ce_encap_error_strings[] = {
  27 #define _(sym,string) string,
  28   foreach_dslite_error
  29 #undef _
  30 };
  31
  32 static uword
  33 dslite_ce_encap_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
  34                          vlib_frame_t * frame)
  35 {
  36   u32 n_left_from, *from, *to_next;
  37   dslite_ce_encap_next_t next_index;
  38   dslite_main_t *dm = &dslite_main;
  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_ENCAP_NEXT_IP6_LOOKUP;
  55           u8 error0 = DSLITE_ERROR_CE_ENCAP;
  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           ip40 = vlib_buffer_get_current (b0);
  70           proto0 = ip_proto_to_snat_proto (ip40->protocol);
  71
  72           if (PREDICT_FALSE (proto0 == ~0))
  73             {
  74               error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
  75               next0 = DSLITE_CE_ENCAP_NEXT_DROP;
  76               goto trace0;
  77             }
  78
  79           /* Construct IPv6 header */
  80           vlib_buffer_advance (b0, -(sizeof (ip6_header_t)));
  81           ip60 = vlib_buffer_get_current (b0);
  82           ip60->ip_version_traffic_class_and_flow_label =
  83             clib_host_to_net_u32 ((6 << 28) + (ip40->tos << 20));
  84           ip60->payload_length = ip40->length;
  85           ip60->protocol = IP_PROTOCOL_IP_IN_IP;
  86           ip60->hop_limit = ip40->ttl;
  87           ip60->dst_address.as_u64[0] = dm->aftr_ip6_addr.as_u64[0];
  88           ip60->dst_address.as_u64[1] = dm->aftr_ip6_addr.as_u64[1];
  89           ip60->src_address.as_u64[0] = dm->b4_ip6_addr.as_u64[0];
  90           ip60->src_address.as_u64[1] = dm->b4_ip6_addr.as_u64[1];
  91
  92         trace0:
  93           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
  94                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
  95             {
  96               dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
  97               t->next_index = next0;
  98             }
  99
 100           b0->error = node->errors[error0];
 101
 102           /* verify speculative enqueue, maybe switch current next frame */
 103           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 104                                            n_left_to_next, bi0, next0);
 105         }
 106       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 107     }
 108
 109   return frame->n_vectors;
 110 }
 111
 112 /* *INDENT-OFF* */
 113 VLIB_REGISTER_NODE (dslite_ce_encap_node) = {
 114   .function = dslite_ce_encap_node_fn,
 115   .name = "dslite-ce-encap",
 116   .vector_size = sizeof (u32),
 117   .format_trace = format_dslite_ce_trace,
 118   .type = VLIB_NODE_TYPE_INTERNAL,
 119   .n_errors = ARRAY_LEN (dslite_ce_encap_error_strings),
 120   .error_strings = dslite_ce_encap_error_strings,
 121   .n_next_nodes = DSLITE_CE_ENCAP_N_NEXT,
 122   /* edit / add dispositions here */
 123   .next_nodes = {
 124     [DSLITE_CE_ENCAP_NEXT_DROP] = "error-drop",
 125     [DSLITE_CE_ENCAP_NEXT_IP6_LOOKUP] = "ip6-lookup",
 126   },
 127 };
 128 /* *INDENT-ON* */
 129
 130 VLIB_NODE_FUNCTION_MULTIARCH (dslite_ce_encap_node, dslite_ce_encap_node_fn);
 131
 132 /*
 133  * fd.io coding-style-patch-verification: ON
 134  *
 135  * Local Variables:
 136  * eval: (c-set-style "gnu")
 137  * End:
 138  */