src/plugins/srv6-am/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 <vppinfra/error.h>
  18 #include <srv6-am/am.h>
  19
  20
  21 /******************************* Packet tracing *******************************/
  22
  23 typedef struct
  24 {
  25   u32 localsid_index;
  26 } srv6_am_localsid_trace_t;
  27
  28 typedef struct
  29 {
  30   ip6_address_t src, dst;
  31 } srv6_am_rewrite_trace_t;
  32
  33 static u8 *
  34 format_srv6_am_localsid_trace (u8 * s, va_list * args)
  35 {
  36   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  37   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  38   srv6_am_localsid_trace_t *t = va_arg (*args, srv6_am_localsid_trace_t *);
  39
  40   return format (s, "SRv6-AM-localsid: localsid_index %d", t->localsid_index);
  41 }
  42
  43 static u8 *
  44 format_srv6_am_rewrite_trace (u8 * s, va_list * args)
  45 {
  46   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  47   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  48   srv6_am_rewrite_trace_t *t = va_arg (*args, srv6_am_rewrite_trace_t *);
  49
  50   return format (s, "SRv6-AM-rewrite: src %U dst %U",
  51                  format_ip6_address, &t->src, format_ip6_address, &t->dst);
  52 }
  53
  54
  55 /***************************** Node registration ******************************/
  56
  57 vlib_node_registration_t srv6_am_rewrite_node;
  58
  59
  60 /****************************** Packet counters *******************************/
  61
  62 #define foreach_srv6_am_rewrite_counter \
  63 _(PROCESSED, "srv6-am rewritten packets") \
  64 _(NO_SRH, "(Error) No SRH.")
  65
  66 typedef enum
  67 {
  68 #define _(sym,str) SRV6_AM_REWRITE_COUNTER_##sym,
  69   foreach_srv6_am_rewrite_counter
  70 #undef _
  71     SRV6_AM_REWRITE_N_COUNTERS,
  72 } srv6_am_rewrite_counters;
  73
  74 static char *srv6_am_rewrite_counter_strings[] = {
  75 #define _(sym,string) string,
  76   foreach_srv6_am_rewrite_counter
  77 #undef _
  78 };
  79
  80
  81 /********************************* Next nodes *********************************/
  82
  83 typedef enum
  84 {
  85   SRV6_AM_LOCALSID_NEXT_ERROR,
  86   SRV6_AM_LOCALSID_NEXT_REWRITE,
  87   SRV6_AM_LOCALSID_N_NEXT,
  88 } srv6_am_localsid_next_t;
  89
  90 typedef enum
  91 {
  92   SRV6_AM_REWRITE_NEXT_ERROR,
  93   SRV6_AM_REWRITE_NEXT_LOOKUP,
  94   SRV6_AM_REWRITE_N_NEXT,
  95 } srv6_am_rewrite_next_t;
  96
  97
  98 /******************************* Local SID node *******************************/
  99
 100 /**
 101  * @brief SRv6 masquerading.
 102  */
 103 static_always_inline void
 104 end_am_processing (vlib_buffer_t * b0,
 105                    ip6_header_t * ip0,
 106                    ip6_sr_header_t * sr0,
 107                    ip6_sr_localsid_t * ls0, u32 * next0)
 108 {
 109   ip6_address_t *new_dst0;
 110
 111   if (PREDICT_FALSE (ip0->protocol != IP_PROTOCOL_IPV6_ROUTE ||
 112                      sr0->type != ROUTING_HEADER_TYPE_SR))
 113     {
 114       *next0 = SRV6_AM_LOCALSID_NEXT_ERROR;
 115       return;
 116     }
 117
 118   if (PREDICT_FALSE (sr0->segments_left == 0))
 119     {
 120       *next0 = SRV6_AM_LOCALSID_NEXT_ERROR;
 121       return;
 122     }
 123
 124   /* Decrement Segments Left */
 125   sr0->segments_left -= 1;
 126
 127   /* Set Destination Address to Last Segment (index 0) */
 128   new_dst0 = (ip6_address_t *) (sr0->segments);
 129   ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
 130   ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];
 131
 132   /* Set Xconnect adjacency to VNF */
 133   vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0->nh_adj;
 134 }
 135
 136 /**
 137  * @brief Graph node for applying SRv6 masquerading.
 138  */
 139 static uword
 140 srv6_am_localsid_fn (vlib_main_t * vm,
 141                      vlib_node_runtime_t * node, vlib_frame_t * frame)
 142 {
 143   ip6_sr_main_t *sm = &sr_main;
 144   u32 n_left_from, next_index, *from, *to_next;
 145
 146   from = vlib_frame_vector_args (frame);
 147   n_left_from = frame->n_vectors;
 148   next_index = node->cached_next_index;
 149
 150   u32 thread_index = vm->thread_index;
 151
 152   while (n_left_from > 0)
 153     {
 154       u32 n_left_to_next;
 155
 156       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 157
 158       /* TODO: Dual/quad loop */
 159
 160       while (n_left_from > 0 && n_left_to_next > 0)
 161         {
 162           u32 bi0;
 163           vlib_buffer_t *b0;
 164           ip6_header_t *ip0 = 0;
 165           ip6_sr_header_t *sr0;
 166           ip6_sr_localsid_t *ls0;
 167           u32 next0 = SRV6_AM_LOCALSID_NEXT_REWRITE;
 168
 169           bi0 = from[0];
 170           to_next[0] = bi0;
 171           from += 1;
 172           to_next += 1;
 173           n_left_from -= 1;
 174           n_left_to_next -= 1;
 175
 176           b0 = vlib_get_buffer (vm, bi0);
 177           ip0 = vlib_buffer_get_current (b0);
 178           sr0 = (ip6_sr_header_t *) (ip0 + 1);
 179
 180           /* Lookup the SR End behavior based on IP DA (adj) */
 181           ls0 = pool_elt_at_index (sm->localsids,
 182                                    vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
 183
 184           /* SRH processing */
 185           end_am_processing (b0, ip0, sr0, ls0, &next0);
 186
 187           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 188             {
 189               srv6_am_localsid_trace_t *tr =
 190                 vlib_add_trace (vm, node, b0, sizeof *tr);
 191               tr->localsid_index = ls0 - sm->localsids;
 192             }
 193
 194           /* This increments the SRv6 per LocalSID counters. */
 195           vlib_increment_combined_counter (((next0 ==
 196                                              SRV6_AM_LOCALSID_NEXT_ERROR) ?
 197                                             &(sm->sr_ls_invalid_counters) :
 198                                             &(sm->sr_ls_valid_counters)),
 199                                            thread_index, ls0 - sm->localsids,
 200                                            1, vlib_buffer_length_in_chain (vm,
 201                                                                            b0));
 202
 203           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 204                                            n_left_to_next, bi0, next0);
 205         }
 206
 207       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 208     }
 209
 210   return frame->n_vectors;
 211 }
 212
 213 VLIB_REGISTER_NODE (srv6_am_localsid_node) = {
 214   .function = srv6_am_localsid_fn,
 215   .name = "srv6-am-localsid",
 216   .vector_size = sizeof (u32),
 217   .format_trace = format_srv6_am_localsid_trace,
 218   .type = VLIB_NODE_TYPE_INTERNAL,
 219   .n_next_nodes = SRV6_AM_LOCALSID_N_NEXT,
 220   .next_nodes = {
 221     [SRV6_AM_LOCALSID_NEXT_REWRITE] = "ip6-rewrite",
 222     [SRV6_AM_LOCALSID_NEXT_ERROR] = "error-drop",
 223   },
 224 };
 225
 226
 227 /******************************* Rewriting node *******************************/
 228
 229 /**
 230  * @brief SRv6 de-masquerading.
 231  */
 232 static_always_inline void
 233 end_am_rewriting (vlib_node_runtime_t * node,
 234                   vlib_buffer_t * b0,
 235                   ip6_header_t * ip0, ip6_sr_header_t * sr0, u32 * next0)
 236 {
 237   if (PREDICT_FALSE (ip0->protocol != IP_PROTOCOL_IPV6_ROUTE ||
 238                      sr0->type != ROUTING_HEADER_TYPE_SR))
 239     {
 240       b0->error = node->errors[SRV6_AM_REWRITE_COUNTER_NO_SRH];
 241       *next0 = SRV6_AM_REWRITE_NEXT_ERROR;
 242       return;
 243     }
 244
 245   /* Restore Destination Address to active segment (index SL) */
 246   if (sr0->segments_left != 0)
 247     {
 248       ip6_address_t *new_dst0;
 249       new_dst0 = (ip6_address_t *) (sr0->segments) + sr0->segments_left;
 250       ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
 251       ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];
 252     }
 253 }
 254
 255 /**
 256  * @brief Graph node for applying SRv6 de-masquerading.
 257  */
 258 static uword
 259 srv6_am_rewrite_fn (vlib_main_t * vm,
 260                     vlib_node_runtime_t * node, vlib_frame_t * frame)
 261 {
 262   u32 n_left_from, next_index, *from, *to_next;
 263   u32 cnt_packets = 0;
 264
 265   from = vlib_frame_vector_args (frame);
 266   n_left_from = frame->n_vectors;
 267   next_index = node->cached_next_index;
 268
 269   while (n_left_from > 0)
 270     {
 271       u32 n_left_to_next;
 272
 273       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 274
 275       /* TODO: Dual/quad loop */
 276
 277       while (n_left_from > 0 && n_left_to_next > 0)
 278         {
 279           u32 bi0;
 280           vlib_buffer_t *b0;
 281           ip6_header_t *ip0 = 0;
 282           ip6_sr_header_t *sr0;
 283           u32 next0 = SRV6_AM_REWRITE_NEXT_LOOKUP;
 284
 285           bi0 = from[0];
 286           to_next[0] = bi0;
 287           from += 1;
 288           to_next += 1;
 289           n_left_from -= 1;
 290           n_left_to_next -= 1;
 291
 292           b0 = vlib_get_buffer (vm, bi0);
 293           ip0 = vlib_buffer_get_current (b0);
 294           sr0 = (ip6_sr_header_t *) (ip0 + 1);
 295
 296           /* SRH processing */
 297           end_am_rewriting (node, b0, ip0, sr0, &next0);
 298
 299           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 300               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 301             {
 302               srv6_am_rewrite_trace_t *tr =
 303                 vlib_add_trace (vm, node, b0, sizeof *tr);
 304               clib_memcpy_fast (tr->src.as_u8, ip0->src_address.as_u8,
 305                                 sizeof tr->src.as_u8);
 306               clib_memcpy_fast (tr->dst.as_u8, ip0->dst_address.as_u8,
 307                                 sizeof tr->dst.as_u8);
 308             }
 309
 310           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 311                                            n_left_to_next, bi0, next0);
 312
 313           cnt_packets++;
 314         }
 315
 316       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 317     }
 318
 319   /* Update counters */
 320   vlib_node_increment_counter (vm, srv6_am_rewrite_node.index,
 321                                SRV6_AM_REWRITE_COUNTER_PROCESSED,
 322                                cnt_packets);
 323
 324   return frame->n_vectors;
 325 }
 326
 327 VLIB_REGISTER_NODE (srv6_am_rewrite_node) = {
 328   .function = srv6_am_rewrite_fn,
 329   .name = "srv6-am-rewrite",
 330   .vector_size = sizeof (u32),
 331   .format_trace = format_srv6_am_rewrite_trace,
 332   .type = VLIB_NODE_TYPE_INTERNAL,
 333   .n_errors = SRV6_AM_REWRITE_N_COUNTERS,
 334   .error_strings = srv6_am_rewrite_counter_strings,
 335   .n_next_nodes = SRV6_AM_REWRITE_N_NEXT,
 336   .next_nodes = {
 337       [SRV6_AM_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 338       [SRV6_AM_REWRITE_NEXT_ERROR] = "error-drop",
 339   },
 340 };
 341
 342 /*
 343 * fd.io coding-style-patch-verification: ON
 344 *
 345 * Local Variables:
 346 * eval: (c-set-style "gnu")
 347 * End:
 348 */