src/examples/srv6-sample-localsid/node.c

   1 /*
   2  * Copyright (c) 2015 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 <vlib/vlib.h>
  16 #include <vnet/vnet.h>
  17 #include <vnet/pg/pg.h>
  18 #include <vppinfra/error.h>
  19 #include <srv6-localsid/srv6_localsid_sample.h>
  20
  21 typedef struct {
  22   u32 localsid_index;
  23 } srv6_localsid_sample_trace_t;
  24
  25 /* packet trace format function */
  26 static u8 * format_srv6_localsid_sample_trace (u8 * s, va_list * args)
  27 {
  28   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  29   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  30   srv6_localsid_sample_trace_t * t = va_arg (*args, srv6_localsid_sample_trace_t *);
  31   s = format (s, "SRv6-sample-localsid: localsid_index %d\n",
  32               t->localsid_index);
  33   return s;
  34 }
  35
  36 vlib_node_registration_t srv6_localsid_sample_node;
  37
  38 #define foreach_srv6_localsid_counter \
  39 _(PROCESSED, "srv6-sample-localsid processed packets") \
  40 _(NO_SRH, "(Error) No SRH.")
  41
  42 typedef enum {
  43 #define _(sym,str) SRV6_LOCALSID_COUNTER_##sym,
  44   foreach_srv6_localsid_counter
  45 #undef _
  46   SRV6_LOCALSID_N_COUNTERS,
  47 } srv6_localsid_sample_counters;
  48
  49 static char * srv6_localsid_counter_strings[] = {
  50 #define _(sym,string) string,
  51   foreach_srv6_localsid_counter
  52 #undef _
  53 };
  54
  55 typedef enum {
  56   SRV6_SAMPLE_LOCALSID_NEXT_ERROR,
  57   SRV6_SAMPLE_LOCALSID_NEXT_IP6LOOKUP,
  58   SRV6_SAMPLE_LOCALSID_N_NEXT,
  59 } srv6_localsid_sample_next_t;
  60
  61 /**
  62  * @brief Function doing End processing.
  63  */
  64 //Fixme: support OAM (hop-by-hop header) here!
  65 static_always_inline void
  66 end_srh_processing (vlib_node_runtime_t * node,
  67                     vlib_buffer_t * b0,
  68                     ip6_header_t * ip0,
  69                     ip6_sr_header_t * sr0,
  70                     u32 * next0)
  71 {
  72   ip6_address_t *new_dst0;
  73
  74   if(PREDICT_TRUE(ip0->protocol == IP_PROTOCOL_IPV6_ROUTE))
  75   {
  76     if(PREDICT_TRUE(sr0->type == ROUTING_HEADER_TYPE_SR))
  77     {
  78       if(PREDICT_TRUE(sr0->segments_left != 0))
  79       {
  80         sr0->segments_left -= 1;
  81         new_dst0 = (ip6_address_t *)(sr0->segments);
  82         new_dst0 += sr0->segments_left;
  83         ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
  84         ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];
  85       }
  86       else
  87       {
  88         *next0 = SRV6_SAMPLE_LOCALSID_NEXT_ERROR;
  89         b0->error = node->errors[SRV6_LOCALSID_COUNTER_NO_SRH];
  90       }
  91     }
  92     else
  93     {
  94       /* Error. Routing header of type != SR */
  95       *next0 = SRV6_SAMPLE_LOCALSID_NEXT_ERROR;
  96       b0->error = node->errors[SRV6_LOCALSID_COUNTER_NO_SRH];
  97     }
  98   }
  99 }
 100
 101 /*
 102  * @brief SRv6 Sample Localsid graph node
 103  * WARNING: YOU MUST DO THE DUAL LOOP
 104  */
 105 static uword
 106 srv6_localsid_sample_fn (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 107 {
 108   u32 n_left_from, * from, * to_next;
 109   u32 next_index;
 110   u32 pkts_swapped = 0;
 111
 112   ip6_sr_main_t * sm = &sr_main;
 113
 114   from = vlib_frame_vector_args (frame);
 115   n_left_from = frame->n_vectors;
 116   next_index = node->cached_next_index;
 117   u32 thread_index = vlib_get_thread_index ();
 118
 119   while (n_left_from > 0)
 120   {
 121     u32 n_left_to_next;
 122
 123     vlib_get_next_frame (vm, node, next_index,
 124                    to_next, n_left_to_next);
 125
 126     while (n_left_from > 0 && n_left_to_next > 0)
 127     {
 128       u32 bi0;
 129       vlib_buffer_t * b0;
 130       ip6_header_t * ip0 = 0;
 131       ip6_sr_header_t * sr0;
 132       u32 next0 = SRV6_SAMPLE_LOCALSID_NEXT_IP6LOOKUP;
 133       ip6_sr_localsid_t *ls0;
 134       srv6_localsid_sample_per_sid_memory_t *ls0_mem;
 135
 136       bi0 = from[0];
 137       to_next[0] = bi0;
 138       from += 1;
 139       to_next += 1;
 140       n_left_from -= 1;
 141       n_left_to_next -= 1;
 142
 143       b0 = vlib_get_buffer (vm, bi0);
 144       ip0 = vlib_buffer_get_current (b0);
 145       sr0 = (ip6_sr_header_t *)(ip0+1);
 146
 147       /* Lookup the SR End behavior based on IP DA (adj) */
 148       ls0 = pool_elt_at_index (sm->localsids, vnet_buffer(b0)->ip.adj_index[VLIB_TX]);
 149       ls0_mem = ls0->plugin_mem;
 150
 151       /* SRH processing */
 152       end_srh_processing (node, b0, ip0, sr0, &next0);
 153
 154       /* ==================================================================== */
 155       /* INSERT CODE HERE */
 156       /* Example starts here */
 157       //In this example we are changing the next VRF table by the one in CLI
 158       vnet_buffer(b0)->sw_if_index[VLIB_TX] = ls0_mem->fib_table;
 159       /* Example finishes here */
 160       /* ==================================================================== */
 161
 162       if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
 163       {
 164         srv6_localsid_sample_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
 165         tr->localsid_index = ls0 - sm->localsids;
 166       }
 167
 168       /* This increments the SRv6 per LocalSID counters.*/
 169       vlib_increment_combined_counter
 170         (((next0 == SRV6_SAMPLE_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) : &(sm->sr_ls_valid_counters)),
 171         thread_index,
 172         ls0 - sm->localsids,
 173         1, vlib_buffer_length_in_chain (vm, b0));
 174
 175       vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 176         n_left_to_next, bi0, next0);
 177
 178       pkts_swapped ++;
 179     }
 180     vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 181
 182   }
 183
 184   return frame->n_vectors;
 185 }
 186
 187 VLIB_REGISTER_NODE (srv6_localsid_sample_node) = {
 188   .function = srv6_localsid_sample_fn,
 189   .name = "srv6-localsid-sample",
 190   .vector_size = sizeof (u32),
 191   .format_trace = format_srv6_localsid_sample_trace,
 192   .type = VLIB_NODE_TYPE_INTERNAL,
 193   .n_errors = SRV6_LOCALSID_N_COUNTERS,
 194   .error_strings = srv6_localsid_counter_strings,
 195   .n_next_nodes = SRV6_SAMPLE_LOCALSID_N_NEXT,
 196   .next_nodes = {
 197         [SRV6_SAMPLE_LOCALSID_NEXT_IP6LOOKUP] = "ip6-lookup",
 198         [SRV6_SAMPLE_LOCALSID_NEXT_ERROR] = "error-drop",
 199     },
 200 };