src/vnet/adj/adj_nsh.c

   1 /*
   2  * Copyright (c) 2017 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
  16 #include <vnet/vnet.h>
  17 #include <vnet/adj/adj_nsh.h>
  18 #include <vnet/ip/ip.h>
  19
  20 nsh_main_dummy_t nsh_main_dummy;
  21
  22 /**
  23  * @brief Trace data for a NSH Midchain
  24  */
  25 typedef struct adj_nsh_trace_t_ {
  26     /** Adjacency index taken. */
  27     u32 adj_index;
  28 } adj_nsh_trace_t;
  29
  30 static u8 *
  31 format_adj_nsh_trace (u8 * s, va_list * args)
  32 {
  33     CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  34     CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  35     adj_nsh_trace_t * t = va_arg (*args, adj_nsh_trace_t *);
  36
  37     s = format (s, "adj-idx %d : %U",
  38                 t->adj_index,
  39                 format_ip_adjacency, t->adj_index, FORMAT_IP_ADJACENCY_NONE);
  40     return s;
  41 }
  42
  43 typedef enum adj_nsh_rewrite_next_t_
  44 {
  45     ADJ_NSH_REWRITE_NEXT_DROP,
  46 } adj_gpe_rewrite_next_t;
  47
  48 always_inline uword
  49 adj_nsh_rewrite_inline (vlib_main_t * vm,
  50                        vlib_node_runtime_t * node,
  51                        vlib_frame_t * frame,
  52                        int is_midchain)
  53 {
  54     u32 * from = vlib_frame_vector_args (frame);
  55     u32 n_left_from, n_left_to_next, * to_next, next_index;
  56     u32 thread_index = vlib_get_thread_index();
  57
  58     n_left_from = frame->n_vectors;
  59     next_index = node->cached_next_index;
  60
  61     while (n_left_from > 0)
  62     {
  63         vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  64
  65         while (n_left_from > 0 && n_left_to_next > 0)
  66         {
  67             ip_adjacency_t * adj0;
  68             vlib_buffer_t * p0;
  69             char *h0;
  70             u32 pi0, rw_len0, adj_index0, next0 = 0;
  71             u32 tx_sw_if_index0;
  72
  73             pi0 = to_next[0] = from[0];
  74             from += 1;
  75             n_left_from -= 1;
  76             to_next += 1;
  77             n_left_to_next -= 1;
  78
  79             p0 = vlib_get_buffer (vm, pi0);
  80             h0 = vlib_buffer_get_current (p0);
  81
  82             adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
  83
  84             /* We should never rewrite a pkt using the MISS adjacency */
  85             ASSERT(adj_index0);
  86
  87             adj0 = adj_get (adj_index0);
  88
  89             /* Guess we are only writing on simple IP4 header. */
  90             vnet_rewrite_one_header(adj0[0], h0, sizeof(ip4_header_t));
  91
  92             /* Update packet buffer attributes/set output interface. */
  93             rw_len0 = adj0[0].rewrite_header.data_bytes;
  94             vnet_buffer(p0)->ip.save_rewrite_length = rw_len0;
  95
  96             vlib_increment_combined_counter(&adjacency_counters,
  97                                             thread_index,
  98                                             adj_index0,
  99                                             /* packet increment */ 0,
 100                                             /* byte increment */ rw_len0);
 101
 102             /* Check MTU of outgoing interface. */
 103             if (PREDICT_TRUE((vlib_buffer_length_in_chain (vm, p0)  <=
 104                               adj0[0].rewrite_header.max_l3_packet_bytes)))
 105             {
 106                 /* Don't adjust the buffer for ttl issue; icmp-error node wants
 107                  * to see the IP headerr */
 108                 p0->current_data -= rw_len0;
 109                 p0->current_length += rw_len0;
 110                 tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
 111
 112                 if (is_midchain)
 113                 {
 114                     adj0->sub_type.midchain.fixup_func(vm, adj0, p0);
 115                 }
 116
 117                 vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
 118
 119                 /*
 120                  * Follow the feature ARC. this will result eventually in
 121                  * the midchain-tx node
 122                  */
 123                 vnet_feature_arc_start (nsh_main_dummy.output_feature_arc_index,
 124                                         tx_sw_if_index0, &next0, p0);
 125             }
 126             else
 127             {
 128                 /* can't fragment NSH */
 129                 next0 = ADJ_NSH_REWRITE_NEXT_DROP;
 130             }
 131
 132             if (PREDICT_FALSE(p0->flags & VLIB_BUFFER_IS_TRACED))
 133             {
 134                 adj_nsh_trace_t *tr = vlib_add_trace (vm, node,
 135                                                      p0, sizeof (*tr));
 136                 tr->adj_index = vnet_buffer(p0)->ip.adj_index[VLIB_TX];
 137             }
 138
 139             vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 140                                              to_next, n_left_to_next,
 141                                              pi0, next0);
 142         }
 143
 144         vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 145     }
 146
 147     return frame->n_vectors;
 148 }
 149
 150 static uword
 151 adj_nsh_rewrite (vlib_main_t * vm,
 152                 vlib_node_runtime_t * node,
 153                 vlib_frame_t * frame)
 154 {
 155     return adj_nsh_rewrite_inline (vm, node, frame, 0);
 156 }
 157
 158 static uword
 159 adj_nsh_midchain (vlib_main_t * vm,
 160                  vlib_node_runtime_t * node,
 161                  vlib_frame_t * frame)
 162 {
 163     return adj_nsh_rewrite_inline (vm, node, frame, 1);
 164 }
 165
 166 VLIB_REGISTER_NODE (adj_nsh_rewrite_node) = {
 167     .function = adj_nsh_rewrite,
 168     .name = "adj-nsh-rewrite",
 169     .vector_size = sizeof (u32),
 170
 171     .format_trace = format_adj_nsh_trace,
 172
 173     .n_next_nodes = 1,
 174     .next_nodes = {
 175         [ADJ_NSH_REWRITE_NEXT_DROP] = "error-drop",
 176     },
 177 };
 178
 179 VLIB_NODE_FUNCTION_MULTIARCH (adj_nsh_rewrite_node, adj_nsh_rewrite)
 180
 181 VLIB_REGISTER_NODE (adj_nsh_midchain_node) = {
 182     .function = adj_nsh_midchain,
 183     .name = "adj-nsh-midchain",
 184     .vector_size = sizeof (u32),
 185
 186     .format_trace = format_adj_nsh_trace,
 187
 188     .n_next_nodes = 1,
 189     .next_nodes = {
 190         [ADJ_NSH_REWRITE_NEXT_DROP] = "error-drop",
 191     },
 192 };
 193
 194 VLIB_NODE_FUNCTION_MULTIARCH (adj_nsh_midchain_node, adj_nsh_midchain)
 195
 196 /* Built-in ip4 tx feature path definition */
 197 /* *INDENT-OFF* */
 198 VNET_FEATURE_ARC_INIT (nsh_output, static) =
 199 {
 200   .arc_name  = "nsh-output",
 201   .start_nodes = VNET_FEATURES ("adj-nsh-midchain"),
 202   .arc_index_ptr = &nsh_main_dummy.output_feature_arc_index,
 203 };
 204
 205 VNET_FEATURE_INIT (nsh_tx_drop, static) =
 206 {
 207   .arc_name = "nsh-output",
 208   .node_name = "error-drop",
 209   .runs_before = 0,     /* not before any other features */
 210 };
 211 /* *INDENT-ON* */