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