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 static_always_inline void
  65 end_srh_processing (vlib_node_runtime_t * node,
  66         vlib_buffer_t * b0,
  67         ip6_header_t * ip0,
  68         ip6_sr_header_t * sr0,
  69         ip6_sr_localsid_t * ls0,
  70         u32 * next0,
  71         u8 psp,
  72         ip6_ext_header_t * prev0)
  73 {
  74   ip6_address_t *new_dst0;
  75
  76   if (PREDICT_TRUE (sr0->type == ROUTING_HEADER_TYPE_SR))
  77   {
  78     if (sr0->segments_left == 1 && psp)
  79     {
  80       u32 new_l0, sr_len;
  81       u64 *copy_dst0, *copy_src0;
  82       u32 copy_len_u64s0 = 0;
  83
  84       ip0->dst_address.as_u64[0] = sr0->segments->as_u64[0];
  85       ip0->dst_address.as_u64[1] = sr0->segments->as_u64[1];
  86
  87       /* Remove the SRH taking care of the rest of IPv6 ext header */
  88       if (prev0)
  89         prev0->next_hdr = sr0->protocol;
  90       else
  91         ip0->protocol = sr0->protocol;
  92
  93       sr_len = ip6_ext_header_len (sr0);
  94       vlib_buffer_advance (b0, sr_len);
  95       new_l0 = clib_net_to_host_u16 (ip0->payload_length) - sr_len;
  96       ip0->payload_length = clib_host_to_net_u16 (new_l0);
  97       copy_src0 = (u64 *) ip0;
  98       copy_dst0 = copy_src0 + (sr0->length + 1);
  99       /* number of 8 octet units to copy
 100        * By default in absence of extension headers it is equal to length of ip6 header
 101        * With extension headers it number of 8 octet units of ext headers preceding
 102        * SR header
 103        */
 104       copy_len_u64s0 =
 105         (((u8 *) sr0 - (u8 *) ip0) - sizeof (ip6_header_t)) >> 3;
 106       copy_dst0[4 + copy_len_u64s0] = copy_src0[4 + copy_len_u64s0];
 107       copy_dst0[3 + copy_len_u64s0] = copy_src0[3 + copy_len_u64s0];
 108       copy_dst0[2 + copy_len_u64s0] = copy_src0[2 + copy_len_u64s0];
 109       copy_dst0[1 + copy_len_u64s0] = copy_src0[1 + copy_len_u64s0];
 110       copy_dst0[0 + copy_len_u64s0] = copy_src0[0 + copy_len_u64s0];
 111
 112       int i;
 113       for (i = copy_len_u64s0 - 1; i >= 0; i--)
 114       {
 115         copy_dst0[i] = copy_src0[i];
 116       }
 117
 118       if (ls0->behavior == SR_BEHAVIOR_X)
 119       {
 120         vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0->nh_adj;
 121         *next0 = SR_LOCALSID_NEXT_IP6_REWRITE;
 122       }
 123       else if(ls0->behavior == SR_BEHAVIOR_T)
 124       {
 125         vnet_buffer (b0)->sw_if_index[VLIB_TX] = ls0->vrf_index;
 126       }
 127     }
 128     else if (PREDICT_TRUE(sr0->segments_left > 0))
 129     {
 130       sr0->segments_left -= 1;
 131       new_dst0 = (ip6_address_t *) (sr0->segments);
 132       new_dst0 += sr0->segments_left;
 133       ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
 134       ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];
 135
 136       if (ls0->behavior == SR_BEHAVIOR_X)
 137       {
 138         vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0->nh_adj;
 139         *next0 = SR_LOCALSID_NEXT_IP6_REWRITE;
 140       }
 141       else if(ls0->behavior == SR_BEHAVIOR_T)
 142       {
 143         vnet_buffer (b0)->sw_if_index[VLIB_TX] = ls0->vrf_index;
 144       }
 145     }
 146     else
 147     {
 148       *next0 = SR_LOCALSID_NEXT_ERROR;
 149       b0->error = node->errors[SR_LOCALSID_ERROR_NO_MORE_SEGMENTS];
 150     }
 151   }
 152   else
 153   {
 154     /* Error. Routing header of type != SR */
 155     *next0 = SR_LOCALSID_NEXT_ERROR;
 156     b0->error = node->errors[SR_LOCALSID_ERROR_NO_SRH];
 157   }
 158 }
 159
 160 /*
 161  * @brief SRv6 Sample Localsid graph node
 162  * WARNING: YOU MUST DO THE DUAL LOOP
 163  */
 164 static uword
 165 srv6_localsid_sample_fn (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
 166 {
 167   u32 n_left_from, * from, * to_next;
 168   u32 next_index;
 169   u32 pkts_swapped = 0;
 170
 171   ip6_sr_main_t * sm = &sr_main;
 172
 173   from = vlib_frame_vector_args (frame);
 174   n_left_from = frame->n_vectors;
 175   next_index = node->cached_next_index;
 176   u32 thread_index = vlib_get_thread_index ();
 177
 178   while (n_left_from > 0)
 179   {
 180     u32 n_left_to_next;
 181
 182     vlib_get_next_frame (vm, node, next_index,
 183                    to_next, n_left_to_next);
 184
 185     while (n_left_from > 0 && n_left_to_next > 0)
 186     {
 187       u32 bi0;
 188       vlib_buffer_t * b0;
 189       ip6_header_t * ip0 = 0;
 190       ip6_sr_header_t * sr0;
 191       u32 next0 = SRV6_SAMPLE_LOCALSID_NEXT_IP6LOOKUP;
 192       ip6_sr_localsid_t *ls0;
 193       srv6_localsid_sample_per_sid_memory_t *ls0_mem;
 194
 195       bi0 = from[0];
 196       to_next[0] = bi0;
 197       from += 1;
 198       to_next += 1;
 199       n_left_from -= 1;
 200       n_left_to_next -= 1;
 201
 202       b0 = vlib_get_buffer (vm, bi0);
 203       ip0 = vlib_buffer_get_current (b0);
 204       sr0 = (ip6_sr_header_t *)(ip0+1);
 205
 206       /* Lookup the SR End behavior based on IP DA (adj) */
 207       ls0 = pool_elt_at_index (sm->localsids, vnet_buffer(b0)->ip.adj_index[VLIB_TX]);
 208       ls0_mem = ls0->plugin_mem;
 209
 210       /* SRH processing */
 211       sr0 = ip6_ext_header_find (vm, b0, ip0, IP_PROTOCOL_IPV6_ROUTE, NULL);
 212       end_decaps_srh_processing (node, b0, ip0, sr0, ls0, &next0);
 213
 214       /* ==================================================================== */
 215       /* INSERT CODE HERE */
 216       /* Example starts here */
 217       //In this example we are changing the next VRF table by the one in CLI
 218       vnet_buffer(b0)->sw_if_index[VLIB_TX] = ls0_mem->fib_table;
 219       /* Example finishes here */
 220       /* ==================================================================== */
 221
 222       if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
 223       {
 224         srv6_localsid_sample_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
 225         tr->localsid_index = ls0 - sm->localsids;
 226       }
 227
 228       /* This increments the SRv6 per LocalSID counters.*/
 229       vlib_increment_combined_counter
 230         (((next0 == SRV6_SAMPLE_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) : &(sm->sr_ls_valid_counters)),
 231         thread_index,
 232         ls0 - sm->localsids,
 233         1, vlib_buffer_length_in_chain (vm, b0));
 234
 235       vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 236         n_left_to_next, bi0, next0);
 237
 238       pkts_swapped ++;
 239     }
 240     vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 241
 242   }
 243
 244   return frame->n_vectors;
 245 }
 246
 247 VLIB_REGISTER_NODE (srv6_localsid_sample_node) = {
 248   .function = srv6_localsid_sample_fn,
 249   .name = "srv6-localsid-sample",
 250   .vector_size = sizeof (u32),
 251   .format_trace = format_srv6_localsid_sample_trace,
 252   .type = VLIB_NODE_TYPE_INTERNAL,
 253   .n_errors = SRV6_LOCALSID_N_COUNTERS,
 254   .error_strings = srv6_localsid_counter_strings,
 255   .n_next_nodes = SRV6_SAMPLE_LOCALSID_N_NEXT,
 256   .next_nodes = {
 257         [SRV6_SAMPLE_LOCALSID_NEXT_IP6LOOKUP] = "ip6-lookup",
 258         [SRV6_SAMPLE_LOCALSID_NEXT_ERROR] = "error-drop",
 259     },
 260 };