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   u32 cnt_packets = 0;
 146
 147   from = vlib_frame_vector_args (frame);
 148   n_left_from = frame->n_vectors;
 149   next_index = node->cached_next_index;
 150
 151   u32 thread_index = vm->thread_index;
 152
 153   while (n_left_from > 0)
 154     {
 155       u32 n_left_to_next;
 156
 157       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 158
 159       /* TODO: Dual/quad loop */
 160
 161       while (n_left_from > 0 && n_left_to_next > 0)
 162         {
 163           u32 bi0;
 164           vlib_buffer_t *b0;
 165           ip6_header_t *ip0 = 0;
 166           ip6_sr_header_t *sr0;
 167           ip6_sr_localsid_t *ls0;
 168           u32 next0 = SRV6_AM_LOCALSID_NEXT_REWRITE;
 169
 170           bi0 = from[0];
 171           to_next[0] = bi0;
 172           from += 1;
 173           to_next += 1;
 174           n_left_from -= 1;
 175           n_left_to_next -= 1;
 176
 177           b0 = vlib_get_buffer (vm, bi0);
 178           ip0 = vlib_buffer_get_current (b0);
 179           sr0 = (ip6_sr_header_t *) (ip0 + 1);
 180
 181           /* Lookup the SR End behavior based on IP DA (adj) */
 182           ls0 = pool_elt_at_index (sm->localsids,
 183                                    vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
 184
 185           /* SRH processing */
 186           end_am_processing (b0, ip0, sr0, ls0, &next0);
 187
 188           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 189             {
 190               srv6_am_localsid_trace_t *tr =
 191                 vlib_add_trace (vm, node, b0, sizeof *tr);
 192               tr->localsid_index = ls0 - sm->localsids;
 193             }
 194
 195           /* This increments the SRv6 per LocalSID counters. */
 196           vlib_increment_combined_counter (((next0 ==
 197                                              SRV6_AM_LOCALSID_NEXT_ERROR) ?
 198                                             &(sm->sr_ls_invalid_counters) :
 199                                             &(sm->sr_ls_valid_counters)),
 200                                            thread_index, ls0 - sm->localsids,
 201                                            1, vlib_buffer_length_in_chain (vm,
 202                                                                            b0));
 203
 204           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 205                                            n_left_to_next, bi0, next0);
 206
 207           cnt_packets++;
 208         }
 209
 210       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 211     }
 212
 213   return frame->n_vectors;
 214 }
 215
 216 /* *INDENT-OFF* */
 217 VLIB_REGISTER_NODE (srv6_am_localsid_node) = {
 218   .function = srv6_am_localsid_fn,
 219   .name = "srv6-am-localsid",
 220   .vector_size = sizeof (u32),
 221   .format_trace = format_srv6_am_localsid_trace,
 222   .type = VLIB_NODE_TYPE_INTERNAL,
 223   .n_next_nodes = SRV6_AM_LOCALSID_N_NEXT,
 224   .next_nodes = {
 225     [SRV6_AM_LOCALSID_NEXT_REWRITE] = "ip6-rewrite",
 226     [SRV6_AM_LOCALSID_NEXT_ERROR] = "error-drop",
 227   },
 228 };
 229 /* *INDENT-ON* */
 230
 231
 232 /******************************* Rewriting node *******************************/
 233
 234 /**
 235  * @brief SRv6 de-masquerading.
 236  */
 237 static_always_inline void
 238 end_am_rewriting (vlib_node_runtime_t * node,
 239                   vlib_buffer_t * b0,
 240                   ip6_header_t * ip0, ip6_sr_header_t * sr0, u32 * next0)
 241 {
 242   if (PREDICT_FALSE (ip0->protocol != IP_PROTOCOL_IPV6_ROUTE ||
 243                      sr0->type != ROUTING_HEADER_TYPE_SR))
 244     {
 245       b0->error = node->errors[SRV6_AM_REWRITE_COUNTER_NO_SRH];
 246       *next0 = SRV6_AM_REWRITE_NEXT_ERROR;
 247       return;
 248     }
 249
 250   /* Restore Destination Address to active segment (index SL) */
 251   if (sr0->segments_left != 0)
 252     {
 253       ip6_address_t *new_dst0;
 254       new_dst0 = (ip6_address_t *) (sr0->segments) + sr0->segments_left;
 255       ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
 256       ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];
 257     }
 258 }
 259
 260 /**
 261  * @brief Graph node for applying SRv6 de-masquerading.
 262  */
 263 static uword
 264 srv6_am_rewrite_fn (vlib_main_t * vm,
 265                     vlib_node_runtime_t * node, vlib_frame_t * frame)
 266 {
 267   u32 n_left_from, next_index, *from, *to_next;
 268   u32 cnt_packets = 0;
 269
 270   from = vlib_frame_vector_args (frame);
 271   n_left_from = frame->n_vectors;
 272   next_index = node->cached_next_index;
 273
 274   while (n_left_from > 0)
 275     {
 276       u32 n_left_to_next;
 277
 278       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 279
 280       /* TODO: Dual/quad loop */
 281
 282       while (n_left_from > 0 && n_left_to_next > 0)
 283         {
 284           u32 bi0;
 285           vlib_buffer_t *b0;
 286           ip6_header_t *ip0 = 0;
 287           ip6_sr_header_t *sr0;
 288           u32 next0 = SRV6_AM_REWRITE_NEXT_LOOKUP;
 289
 290           bi0 = from[0];
 291           to_next[0] = bi0;
 292           from += 1;
 293           to_next += 1;
 294           n_left_from -= 1;
 295           n_left_to_next -= 1;
 296
 297           b0 = vlib_get_buffer (vm, bi0);
 298           ip0 = vlib_buffer_get_current (b0);
 299           sr0 = (ip6_sr_header_t *) (ip0 + 1);
 300
 301           /* SRH processing */
 302           end_am_rewriting (node, b0, ip0, sr0, &next0);
 303
 304           if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
 305               PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 306             {
 307               srv6_am_rewrite_trace_t *tr =
 308                 vlib_add_trace (vm, node, b0, sizeof *tr);
 309               clib_memcpy_fast (tr->src.as_u8, ip0->src_address.as_u8,
 310                                 sizeof tr->src.as_u8);
 311               clib_memcpy_fast (tr->dst.as_u8, ip0->dst_address.as_u8,
 312                                 sizeof tr->dst.as_u8);
 313             }
 314
 315           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 316                                            n_left_to_next, bi0, next0);
 317
 318           cnt_packets++;
 319         }
 320
 321       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 322     }
 323
 324   /* Update counters */
 325   vlib_node_increment_counter (vm, srv6_am_rewrite_node.index,
 326                                SRV6_AM_REWRITE_COUNTER_PROCESSED,
 327                                cnt_packets);
 328
 329   return frame->n_vectors;
 330 }
 331
 332 /* *INDENT-OFF* */
 333 VLIB_REGISTER_NODE (srv6_am_rewrite_node) = {
 334   .function = srv6_am_rewrite_fn,
 335   .name = "srv6-am-rewrite",
 336   .vector_size = sizeof (u32),
 337   .format_trace = format_srv6_am_rewrite_trace,
 338   .type = VLIB_NODE_TYPE_INTERNAL,
 339   .n_errors = SRV6_AM_REWRITE_N_COUNTERS,
 340   .error_strings = srv6_am_rewrite_counter_strings,
 341   .n_next_nodes = SRV6_AM_REWRITE_N_NEXT,
 342   .next_nodes = {
 343       [SRV6_AM_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
 344       [SRV6_AM_REWRITE_NEXT_ERROR] = "error-drop",
 345   },
 346 };
 347 /* *INDENT-ON* */
 348
 349 /*
 350 * fd.io coding-style-patch-verification: ON
 351 *
 352 * Local Variables:
 353 * eval: (c-set-style "gnu")
 354 * End:
 355 */