src/plugins/nat/nat64_out2in.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  * @file
  17  * @brief NAT64 IPv4 to IPv6 translation (otside to inside network)
  18  */
  19
  20 #include <nat/nat64.h>
  21 #include <nat/nat_reass.h>
  22 #include <vnet/ip/ip4_to_ip6.h>
  23 #include <vnet/fib/ip4_fib.h>
  24 #include <vnet/udp/udp.h>
  25
  26 typedef struct
  27 {
  28   u32 sw_if_index;
  29   u32 next_index;
  30 } nat64_out2in_trace_t;
  31
  32 static u8 *
  33 format_nat64_out2in_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   nat64_out2in_trace_t *t = va_arg (*args, nat64_out2in_trace_t *);
  38
  39   s =
  40     format (s, "NAT64-out2in: sw_if_index %d, next index %d", t->sw_if_index,
  41             t->next_index);
  42
  43   return s;
  44 }
  45
  46 typedef struct
  47 {
  48   u32 sw_if_index;
  49   u32 next_index;
  50   u8 cached;
  51 } nat64_out2in_reass_trace_t;
  52
  53 static u8 *
  54 format_nat64_out2in_reass_trace (u8 * s, va_list * args)
  55 {
  56   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  57   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  58   nat64_out2in_reass_trace_t *t =
  59     va_arg (*args, nat64_out2in_reass_trace_t *);
  60
  61   s =
  62     format (s, "NAT64-out2in-reass: sw_if_index %d, next index %d, status %s",
  63             t->sw_if_index, t->next_index,
  64             t->cached ? "cached" : "translated");
  65
  66   return s;
  67 }
  68
  69 vlib_node_registration_t nat64_out2in_node;
  70 vlib_node_registration_t nat64_out2in_reass_node;
  71 vlib_node_registration_t nat64_out2in_handoff_node;
  72
  73 #define foreach_nat64_out2in_error                       \
  74 _(UNSUPPORTED_PROTOCOL, "Unsupported protocol")          \
  75 _(OUT2IN_PACKETS, "Good out2in packets processed")       \
  76 _(NO_TRANSLATION, "No translation")                      \
  77 _(UNKNOWN, "unknown")                                    \
  78 _(DROP_FRAGMENT, "Drop fragment")                        \
  79 _(MAX_REASS, "Maximum reassemblies exceeded")            \
  80 _(MAX_FRAG, "Maximum fragments per reassembly exceeded")
  81
  82
  83 typedef enum
  84 {
  85 #define _(sym,str) NAT64_OUT2IN_ERROR_##sym,
  86   foreach_nat64_out2in_error
  87 #undef _
  88     NAT64_OUT2IN_N_ERROR,
  89 } nat64_out2in_error_t;
  90
  91 static char *nat64_out2in_error_strings[] = {
  92 #define _(sym,string) string,
  93   foreach_nat64_out2in_error
  94 #undef _
  95 };
  96
  97 typedef enum
  98 {
  99   NAT64_OUT2IN_NEXT_IP6_LOOKUP,
 100   NAT64_OUT2IN_NEXT_IP4_LOOKUP,
 101   NAT64_OUT2IN_NEXT_DROP,
 102   NAT64_OUT2IN_NEXT_REASS,
 103   NAT64_OUT2IN_N_NEXT,
 104 } nat64_out2in_next_t;
 105
 106 typedef struct nat64_out2in_set_ctx_t_
 107 {
 108   vlib_buffer_t *b;
 109   vlib_main_t *vm;
 110   u32 thread_index;
 111 } nat64_out2in_set_ctx_t;
 112
 113 static int
 114 nat64_out2in_tcp_udp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
 115                              void *arg)
 116 {
 117   nat64_main_t *nm = &nat64_main;
 118   nat64_out2in_set_ctx_t *ctx = arg;
 119   nat64_db_bib_entry_t *bibe;
 120   nat64_db_st_entry_t *ste;
 121   ip46_address_t saddr, daddr;
 122   ip6_address_t ip6_saddr;
 123   udp_header_t *udp = ip4_next_header (ip4);
 124   tcp_header_t *tcp = ip4_next_header (ip4);
 125   u8 proto = ip4->protocol;
 126   u16 dport = udp->dst_port;
 127   u16 sport = udp->src_port;
 128   u32 sw_if_index, fib_index;
 129   u16 *checksum;
 130   ip_csum_t csum;
 131   nat64_db_t *db = &nm->db[ctx->thread_index];
 132
 133   sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
 134   fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 135
 136   memset (&saddr, 0, sizeof (saddr));
 137   saddr.ip4.as_u32 = ip4->src_address.as_u32;
 138   memset (&daddr, 0, sizeof (daddr));
 139   daddr.ip4.as_u32 = ip4->dst_address.as_u32;
 140
 141   ste =
 142     nat64_db_st_entry_find (db, &daddr, &saddr, dport, sport, proto,
 143                             fib_index, 0);
 144   if (ste)
 145     {
 146       bibe = nat64_db_bib_entry_by_index (db, proto, ste->bibe_index);
 147       if (!bibe)
 148         return -1;
 149     }
 150   else
 151     {
 152       bibe = nat64_db_bib_entry_find (db, &daddr, dport, proto, fib_index, 0);
 153
 154       if (!bibe)
 155         return -1;
 156
 157       nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
 158       ste =
 159         nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, sport);
 160     }
 161
 162   nat64_session_reset_timeout (ste, ctx->vm);
 163
 164   ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 165   ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 166
 167   ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
 168   ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
 169   udp->dst_port = bibe->in_port;
 170
 171   if (proto == IP_PROTOCOL_UDP)
 172     checksum = &udp->checksum;
 173   else
 174     checksum = &tcp->checksum;
 175   csum = ip_csum_sub_even (*checksum, dport);
 176   csum = ip_csum_add_even (csum, udp->dst_port);
 177   *checksum = ip_csum_fold (csum);
 178
 179   vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 180
 181   return 0;
 182 }
 183
 184 static int
 185 nat64_out2in_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6, void *arg)
 186 {
 187   nat64_main_t *nm = &nat64_main;
 188   nat64_out2in_set_ctx_t *ctx = arg;
 189   nat64_db_bib_entry_t *bibe;
 190   nat64_db_st_entry_t *ste;
 191   ip46_address_t saddr, daddr;
 192   ip6_address_t ip6_saddr;
 193   u32 sw_if_index, fib_index;
 194   icmp46_header_t *icmp = ip4_next_header (ip4);
 195   nat64_db_t *db = &nm->db[ctx->thread_index];
 196
 197   sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
 198   fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 199
 200   memset (&saddr, 0, sizeof (saddr));
 201   saddr.ip4.as_u32 = ip4->src_address.as_u32;
 202   memset (&daddr, 0, sizeof (daddr));
 203   daddr.ip4.as_u32 = ip4->dst_address.as_u32;
 204
 205   if (icmp->type == ICMP6_echo_request || icmp->type == ICMP6_echo_reply)
 206     {
 207       u16 out_id = ((u16 *) (icmp))[2];
 208       ste =
 209         nat64_db_st_entry_find (db, &daddr, &saddr, out_id, 0,
 210                                 IP_PROTOCOL_ICMP, fib_index, 0);
 211
 212       if (ste)
 213         {
 214           bibe =
 215             nat64_db_bib_entry_by_index (db, IP_PROTOCOL_ICMP,
 216                                          ste->bibe_index);
 217           if (!bibe)
 218             return -1;
 219         }
 220       else
 221         {
 222           bibe =
 223             nat64_db_bib_entry_find (db, &daddr, out_id,
 224                                      IP_PROTOCOL_ICMP, fib_index, 0);
 225           if (!bibe)
 226             return -1;
 227
 228           nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
 229           ste =
 230             nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, 0);
 231         }
 232
 233       nat64_session_reset_timeout (ste, ctx->vm);
 234
 235       ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 236       ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 237
 238       ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
 239       ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
 240       ((u16 *) (icmp))[2] = bibe->in_port;
 241
 242       vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 243     }
 244   else
 245     {
 246       ip6_header_t *inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8);
 247
 248       nat64_compose_ip6 (&ip6->src_address, &ip4->src_address,
 249                          vnet_buffer (ctx->b)->sw_if_index[VLIB_TX]);
 250       ip6->dst_address.as_u64[0] = inner_ip6->src_address.as_u64[0];
 251       ip6->dst_address.as_u64[1] = inner_ip6->src_address.as_u64[1];
 252     }
 253
 254   return 0;
 255 }
 256
 257 static int
 258 nat64_out2in_inner_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
 259                                 void *arg)
 260 {
 261   nat64_main_t *nm = &nat64_main;
 262   nat64_out2in_set_ctx_t *ctx = arg;
 263   nat64_db_bib_entry_t *bibe;
 264   nat64_db_st_entry_t *ste;
 265   ip46_address_t saddr, daddr;
 266   u32 sw_if_index, fib_index;
 267   u8 proto = ip4->protocol;
 268   nat64_db_t *db = &nm->db[ctx->thread_index];
 269
 270   sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
 271   fib_index =
 272     fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
 273
 274   memset (&saddr, 0, sizeof (saddr));
 275   saddr.ip4.as_u32 = ip4->src_address.as_u32;
 276   memset (&daddr, 0, sizeof (daddr));
 277   daddr.ip4.as_u32 = ip4->dst_address.as_u32;
 278
 279   if (proto == IP_PROTOCOL_ICMP6)
 280     {
 281       icmp46_header_t *icmp = ip4_next_header (ip4);
 282       u16 out_id = ((u16 *) (icmp))[2];
 283       proto = IP_PROTOCOL_ICMP;
 284
 285       if (!
 286           (icmp->type == ICMP6_echo_request
 287            || icmp->type == ICMP6_echo_reply))
 288         return -1;
 289
 290       ste =
 291         nat64_db_st_entry_find (db, &saddr, &daddr, out_id, 0, proto,
 292                                 fib_index, 0);
 293       if (!ste)
 294         return -1;
 295
 296       bibe = nat64_db_bib_entry_by_index (db, proto, ste->bibe_index);
 297       if (!bibe)
 298         return -1;
 299
 300       ip6->dst_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 301       ip6->dst_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 302       ip6->src_address.as_u64[0] = bibe->in_addr.as_u64[0];
 303       ip6->src_address.as_u64[1] = bibe->in_addr.as_u64[1];
 304       ((u16 *) (icmp))[2] = bibe->in_port;
 305
 306       vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 307     }
 308   else
 309     {
 310       udp_header_t *udp = ip4_next_header (ip4);
 311       tcp_header_t *tcp = ip4_next_header (ip4);
 312       u16 dport = udp->dst_port;
 313       u16 sport = udp->src_port;
 314       u16 *checksum;
 315       ip_csum_t csum;
 316
 317       ste =
 318         nat64_db_st_entry_find (db, &saddr, &daddr, sport, dport, proto,
 319                                 fib_index, 0);
 320       if (!ste)
 321         return -1;
 322
 323       bibe = nat64_db_bib_entry_by_index (db, proto, ste->bibe_index);
 324       if (!bibe)
 325         return -1;
 326
 327       nat64_compose_ip6 (&ip6->dst_address, &daddr.ip4, bibe->fib_index);
 328       ip6->src_address.as_u64[0] = bibe->in_addr.as_u64[0];
 329       ip6->src_address.as_u64[1] = bibe->in_addr.as_u64[1];
 330       udp->src_port = bibe->in_port;
 331
 332       if (proto == IP_PROTOCOL_UDP)
 333         checksum = &udp->checksum;
 334       else
 335         checksum = &tcp->checksum;
 336       if (*checksum)
 337         {
 338           csum = ip_csum_sub_even (*checksum, sport);
 339           csum = ip_csum_add_even (csum, udp->src_port);
 340           *checksum = ip_csum_fold (csum);
 341         }
 342
 343       vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 344     }
 345
 346   return 0;
 347 }
 348
 349 static int
 350 nat64_out2in_unk_proto_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
 351                                void *arg)
 352 {
 353   nat64_main_t *nm = &nat64_main;
 354   nat64_out2in_set_ctx_t *ctx = arg;
 355   nat64_db_bib_entry_t *bibe;
 356   nat64_db_st_entry_t *ste;
 357   ip46_address_t saddr, daddr;
 358   ip6_address_t ip6_saddr;
 359   u32 sw_if_index, fib_index;
 360   u8 proto = ip4->protocol;
 361   nat64_db_t *db = &nm->db[ctx->thread_index];
 362
 363   sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
 364   fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 365
 366   memset (&saddr, 0, sizeof (saddr));
 367   saddr.ip4.as_u32 = ip4->src_address.as_u32;
 368   memset (&daddr, 0, sizeof (daddr));
 369   daddr.ip4.as_u32 = ip4->dst_address.as_u32;
 370
 371   ste =
 372     nat64_db_st_entry_find (db, &daddr, &saddr, 0, 0, proto, fib_index, 0);
 373   if (ste)
 374     {
 375       bibe = nat64_db_bib_entry_by_index (db, proto, ste->bibe_index);
 376       if (!bibe)
 377         return -1;
 378     }
 379   else
 380     {
 381       bibe = nat64_db_bib_entry_find (db, &daddr, 0, proto, fib_index, 0);
 382
 383       if (!bibe)
 384         return -1;
 385
 386       nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
 387       ste = nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, 0);
 388     }
 389
 390   nat64_session_reset_timeout (ste, ctx->vm);
 391
 392   ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 393   ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 394
 395   ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
 396   ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
 397
 398   vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 399
 400   return 0;
 401 }
 402
 403 static uword
 404 nat64_out2in_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 405                       vlib_frame_t * frame)
 406 {
 407   u32 n_left_from, *from, *to_next;
 408   nat64_out2in_next_t next_index;
 409   u32 pkts_processed = 0;
 410   u32 thread_index = vlib_get_thread_index ();
 411
 412   from = vlib_frame_vector_args (frame);
 413   n_left_from = frame->n_vectors;
 414   next_index = node->cached_next_index;
 415   while (n_left_from > 0)
 416     {
 417       u32 n_left_to_next;
 418
 419       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 420
 421       while (n_left_from > 0 && n_left_to_next > 0)
 422         {
 423           u32 bi0;
 424           vlib_buffer_t *b0;
 425           u32 next0;
 426           ip4_header_t *ip40;
 427           u32 proto0;
 428           nat64_out2in_set_ctx_t ctx0;
 429           udp_header_t *udp0;
 430
 431           /* speculatively enqueue b0 to the current next frame */
 432           bi0 = from[0];
 433           to_next[0] = bi0;
 434           from += 1;
 435           to_next += 1;
 436           n_left_from -= 1;
 437           n_left_to_next -= 1;
 438
 439           b0 = vlib_get_buffer (vm, bi0);
 440           ip40 = vlib_buffer_get_current (b0);
 441
 442           ctx0.b = b0;
 443           ctx0.vm = vm;
 444           ctx0.thread_index = thread_index;
 445
 446           next0 = NAT64_OUT2IN_NEXT_IP6_LOOKUP;
 447
 448           proto0 = ip_proto_to_snat_proto (ip40->protocol);
 449
 450           if (PREDICT_FALSE (proto0 == ~0))
 451             {
 452               if (ip4_to_ip6 (b0, nat64_out2in_unk_proto_set_cb, &ctx0))
 453                 {
 454                   next0 = NAT64_OUT2IN_NEXT_DROP;
 455                   b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 456                 }
 457               goto trace0;
 458             }
 459
 460           if (PREDICT_FALSE (ip4_is_fragment (ip40)))
 461             {
 462               next0 = NAT64_OUT2IN_NEXT_REASS;
 463               goto trace0;
 464             }
 465
 466           if (proto0 == SNAT_PROTOCOL_ICMP)
 467             {
 468               if (icmp_to_icmp6
 469                   (b0, nat64_out2in_icmp_set_cb, &ctx0,
 470                    nat64_out2in_inner_icmp_set_cb, &ctx0))
 471                 {
 472                   next0 = NAT64_OUT2IN_NEXT_DROP;
 473                   b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 474                   goto trace0;
 475                 }
 476             }
 477           else
 478             {
 479               if (ip4_to_ip6_tcp_udp (b0, nat64_out2in_tcp_udp_set_cb, &ctx0))
 480                 {
 481                   udp0 = ip4_next_header (ip40);
 482                   /*
 483                    * Send DHCP packets to the ipv4 stack, or we won't
 484                    * be able to use dhcp client on the outside interface
 485                    */
 486                   if ((proto0 == SNAT_PROTOCOL_UDP)
 487                       && (udp0->dst_port ==
 488                           clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_client)))
 489                     {
 490                       next0 = NAT64_OUT2IN_NEXT_IP4_LOOKUP;
 491                       goto trace0;
 492                     }
 493                   next0 = NAT64_OUT2IN_NEXT_DROP;
 494                   b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 495                   goto trace0;
 496                 }
 497             }
 498
 499         trace0:
 500           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 501                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 502             {
 503               nat64_out2in_trace_t *t =
 504                 vlib_add_trace (vm, node, b0, sizeof (*t));
 505               t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 506               t->next_index = next0;
 507             }
 508
 509           pkts_processed += next0 != NAT64_OUT2IN_NEXT_DROP;
 510
 511           /* verify speculative enqueue, maybe switch current next frame */
 512           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 513                                            n_left_to_next, bi0, next0);
 514         }
 515       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 516     }
 517   vlib_node_increment_counter (vm, nat64_out2in_node.index,
 518                                NAT64_OUT2IN_ERROR_OUT2IN_PACKETS,
 519                                pkts_processed);
 520   return frame->n_vectors;
 521 }
 522
 523 /* *INDENT-OFF* */
 524 VLIB_REGISTER_NODE (nat64_out2in_node) = {
 525   .function = nat64_out2in_node_fn,
 526   .name = "nat64-out2in",
 527   .vector_size = sizeof (u32),
 528   .format_trace = format_nat64_out2in_trace,
 529   .type = VLIB_NODE_TYPE_INTERNAL,
 530   .n_errors = ARRAY_LEN (nat64_out2in_error_strings),
 531   .error_strings = nat64_out2in_error_strings,
 532   .n_next_nodes = NAT64_OUT2IN_N_NEXT,
 533   /* edit / add dispositions here */
 534   .next_nodes = {
 535     [NAT64_OUT2IN_NEXT_DROP] = "error-drop",
 536     [NAT64_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup",
 537     [NAT64_OUT2IN_NEXT_IP4_LOOKUP] = "ip4-lookup",
 538     [NAT64_OUT2IN_NEXT_REASS] = "nat64-out2in-reass",
 539   },
 540 };
 541 /* *INDENT-ON* */
 542
 543 VLIB_NODE_FUNCTION_MULTIARCH (nat64_out2in_node, nat64_out2in_node_fn);
 544
 545 typedef struct nat64_out2in_frag_set_ctx_t_
 546 {
 547   vlib_main_t *vm;
 548   vlib_buffer_t *b;
 549   u32 sess_index;
 550   u32 thread_index;
 551   u8 proto;
 552   u8 first_frag;
 553 } nat64_out2in_frag_set_ctx_t;
 554
 555 static int
 556 nat64_out2in_frag_set_cb (ip4_header_t * ip4, ip6_header_t * ip6, void *arg)
 557 {
 558   nat64_main_t *nm = &nat64_main;
 559   nat64_out2in_frag_set_ctx_t *ctx = arg;
 560   nat64_db_st_entry_t *ste;
 561   nat64_db_bib_entry_t *bibe;
 562   udp_header_t *udp = ip4_next_header (ip4);
 563   ip_csum_t csum;
 564   u16 *checksum;
 565   nat64_db_t *db = &nm->db[ctx->thread_index];
 566
 567   ste = nat64_db_st_entry_by_index (db, ctx->proto, ctx->sess_index);
 568   if (!ste)
 569     return -1;
 570
 571   bibe = nat64_db_bib_entry_by_index (db, ctx->proto, ste->bibe_index);
 572   if (!bibe)
 573     return -1;
 574
 575   nat64_session_reset_timeout (ste, ctx->vm);
 576
 577   if (ctx->first_frag)
 578     {
 579       udp->dst_port = bibe->in_port;
 580
 581       if (ip4->protocol == IP_PROTOCOL_UDP)
 582         {
 583           checksum = &udp->checksum;
 584
 585           if (!checksum)
 586             {
 587               u16 udp_len =
 588                 clib_host_to_net_u16 (ip4->length) - sizeof (*ip4);
 589               csum = ip_incremental_checksum (0, udp, udp_len);
 590               csum =
 591                 ip_csum_with_carry (csum, clib_host_to_net_u16 (udp_len));
 592               csum =
 593                 ip_csum_with_carry (csum,
 594                                     clib_host_to_net_u16 (IP_PROTOCOL_UDP));
 595               csum = ip_csum_with_carry (csum, ste->in_r_addr.as_u64[0]);
 596               csum = ip_csum_with_carry (csum, ste->in_r_addr.as_u64[1]);
 597               csum = ip_csum_with_carry (csum, bibe->in_addr.as_u64[0]);
 598               csum = ip_csum_with_carry (csum, bibe->in_addr.as_u64[1]);
 599               *checksum = ~ip_csum_fold (csum);
 600             }
 601           else
 602             {
 603               csum = ip_csum_sub_even (*checksum, bibe->out_addr.as_u32);
 604               csum = ip_csum_sub_even (csum, ste->out_r_addr.as_u32);
 605               csum = ip_csum_sub_even (csum, bibe->out_port);
 606               csum = ip_csum_add_even (csum, ste->in_r_addr.as_u64[0]);
 607               csum = ip_csum_add_even (csum, ste->in_r_addr.as_u64[1]);
 608               csum = ip_csum_add_even (csum, bibe->in_addr.as_u64[0]);
 609               csum = ip_csum_add_even (csum, bibe->in_addr.as_u64[1]);
 610               csum = ip_csum_add_even (csum, bibe->in_port);
 611               *checksum = ip_csum_fold (csum);
 612             }
 613         }
 614       else
 615         {
 616           tcp_header_t *tcp = ip4_next_header (ip4);
 617           checksum = &tcp->checksum;
 618           csum = ip_csum_sub_even (*checksum, bibe->out_addr.as_u32);
 619           csum = ip_csum_sub_even (csum, ste->out_r_addr.as_u32);
 620           csum = ip_csum_sub_even (csum, bibe->out_port);
 621           csum = ip_csum_add_even (csum, ste->in_r_addr.as_u64[0]);
 622           csum = ip_csum_add_even (csum, ste->in_r_addr.as_u64[1]);
 623           csum = ip_csum_add_even (csum, bibe->in_addr.as_u64[0]);
 624           csum = ip_csum_add_even (csum, bibe->in_addr.as_u64[1]);
 625           csum = ip_csum_add_even (csum, bibe->in_port);
 626           *checksum = ip_csum_fold (csum);
 627         }
 628
 629     }
 630
 631   ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 632   ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 633
 634   ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
 635   ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
 636
 637   vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 638
 639   return 0;
 640 }
 641
 642 static uword
 643 nat64_out2in_reass_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 644                             vlib_frame_t * frame)
 645 {
 646   u32 n_left_from, *from, *to_next;
 647   nat64_out2in_next_t next_index;
 648   u32 pkts_processed = 0;
 649   u32 *fragments_to_drop = 0;
 650   u32 *fragments_to_loopback = 0;
 651   nat64_main_t *nm = &nat64_main;
 652   u32 thread_index = vlib_get_thread_index ();
 653
 654   from = vlib_frame_vector_args (frame);
 655   n_left_from = frame->n_vectors;
 656   next_index = node->cached_next_index;
 657
 658   while (n_left_from > 0)
 659     {
 660       u32 n_left_to_next;
 661
 662       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 663
 664       while (n_left_from > 0 && n_left_to_next > 0)
 665         {
 666           u32 bi0;
 667           vlib_buffer_t *b0;
 668           u32 next0;
 669           ip4_header_t *ip40;
 670           u8 cached0 = 0;
 671           u32 sw_if_index0, fib_index0;
 672           udp_header_t *udp0;
 673           nat_reass_ip4_t *reass0;
 674           ip46_address_t saddr0, daddr0;
 675           nat64_db_st_entry_t *ste0;
 676           nat64_db_bib_entry_t *bibe0;
 677           ip6_address_t ip6_saddr0;
 678           nat64_out2in_frag_set_ctx_t ctx0;
 679           nat64_db_t *db = &nm->db[thread_index];
 680
 681           /* speculatively enqueue b0 to the current next frame */
 682           bi0 = from[0];
 683           to_next[0] = bi0;
 684           from += 1;
 685           to_next += 1;
 686           n_left_from -= 1;
 687           n_left_to_next -= 1;
 688
 689           b0 = vlib_get_buffer (vm, bi0);
 690           next0 = NAT64_OUT2IN_NEXT_IP6_LOOKUP;
 691
 692           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 693           fib_index0 =
 694             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 695                                                  sw_if_index0);
 696
 697           ctx0.thread_index = thread_index;
 698
 699           if (PREDICT_FALSE (nat_reass_is_drop_frag (1)))
 700             {
 701               next0 = NAT64_OUT2IN_NEXT_DROP;
 702               b0->error = node->errors[NAT64_OUT2IN_ERROR_DROP_FRAGMENT];
 703               goto trace0;
 704             }
 705
 706           ip40 = vlib_buffer_get_current (b0);
 707
 708           if (PREDICT_FALSE (!(ip40->protocol == IP_PROTOCOL_TCP
 709                                || ip40->protocol == IP_PROTOCOL_UDP)))
 710             {
 711               next0 = NAT64_OUT2IN_NEXT_DROP;
 712               b0->error = node->errors[NAT64_OUT2IN_ERROR_DROP_FRAGMENT];
 713               goto trace0;
 714             }
 715
 716           udp0 = ip4_next_header (ip40);
 717
 718           reass0 = nat_ip4_reass_find_or_create (ip40->src_address,
 719                                                  ip40->dst_address,
 720                                                  ip40->fragment_id,
 721                                                  ip40->protocol,
 722                                                  1, &fragments_to_drop);
 723
 724           if (PREDICT_FALSE (!reass0))
 725             {
 726               next0 = NAT64_OUT2IN_NEXT_DROP;
 727               b0->error = node->errors[NAT64_OUT2IN_ERROR_MAX_REASS];
 728               goto trace0;
 729             }
 730
 731           if (PREDICT_FALSE (ip4_is_first_fragment (ip40)))
 732             {
 733               ctx0.first_frag = 1;
 734
 735               memset (&saddr0, 0, sizeof (saddr0));
 736               saddr0.ip4.as_u32 = ip40->src_address.as_u32;
 737               memset (&daddr0, 0, sizeof (daddr0));
 738               daddr0.ip4.as_u32 = ip40->dst_address.as_u32;
 739
 740               ste0 =
 741                 nat64_db_st_entry_find (db, &daddr0, &saddr0,
 742                                         udp0->dst_port, udp0->src_port,
 743                                         ip40->protocol, fib_index0, 0);
 744               if (!ste0)
 745                 {
 746                   bibe0 =
 747                     nat64_db_bib_entry_find (db, &daddr0, udp0->dst_port,
 748                                              ip40->protocol, fib_index0, 0);
 749                   if (!bibe0)
 750                     {
 751                       next0 = NAT64_OUT2IN_NEXT_DROP;
 752                       b0->error =
 753                         node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 754                       goto trace0;
 755                     }
 756
 757                   nat64_compose_ip6 (&ip6_saddr0, &ip40->src_address,
 758                                      bibe0->fib_index);
 759                   ste0 =
 760                     nat64_db_st_entry_create (db, bibe0, &ip6_saddr0,
 761                                               &saddr0.ip4, udp0->src_port);
 762
 763                   if (!ste0)
 764                     {
 765                       next0 = NAT64_OUT2IN_NEXT_DROP;
 766                       b0->error =
 767                         node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 768                       goto trace0;
 769                     }
 770                 }
 771               reass0->sess_index = nat64_db_st_entry_get_index (db, ste0);
 772               reass0->thread_index = thread_index;
 773
 774               nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
 775             }
 776           else
 777             {
 778               ctx0.first_frag = 0;
 779
 780               if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
 781                 {
 782                   if (nat_ip4_reass_add_fragment (reass0, bi0))
 783                     {
 784                       b0->error = node->errors[NAT64_OUT2IN_ERROR_MAX_FRAG];
 785                       next0 = NAT64_OUT2IN_NEXT_DROP;
 786                       goto trace0;
 787                     }
 788                   cached0 = 1;
 789                   goto trace0;
 790                 }
 791             }
 792
 793           ctx0.sess_index = reass0->sess_index;
 794           ctx0.proto = ip40->protocol;
 795           ctx0.vm = vm;
 796           ctx0.b = b0;
 797
 798           if (ip4_to_ip6_fragmented (b0, nat64_out2in_frag_set_cb, &ctx0))
 799             {
 800               next0 = NAT64_OUT2IN_NEXT_DROP;
 801               b0->error = node->errors[NAT64_OUT2IN_ERROR_UNKNOWN];
 802               goto trace0;
 803             }
 804
 805         trace0:
 806           if (PREDICT_FALSE
 807               ((node->flags & VLIB_NODE_FLAG_TRACE)
 808                && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 809             {
 810               nat64_out2in_reass_trace_t *t =
 811                 vlib_add_trace (vm, node, b0, sizeof (*t));
 812               t->cached = cached0;
 813               t->sw_if_index = sw_if_index0;
 814               t->next_index = next0;
 815             }
 816
 817           if (cached0)
 818             {
 819               n_left_to_next++;
 820               to_next--;
 821             }
 822           else
 823             {
 824               pkts_processed += next0 != NAT64_OUT2IN_NEXT_DROP;
 825
 826               /* verify speculative enqueue, maybe switch current next frame */
 827               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 828                                                to_next, n_left_to_next,
 829                                                bi0, next0);
 830             }
 831
 832           if (n_left_from == 0 && vec_len (fragments_to_loopback))
 833             {
 834               from = vlib_frame_vector_args (frame);
 835               u32 len = vec_len (fragments_to_loopback);
 836               if (len <= VLIB_FRAME_SIZE)
 837                 {
 838                   clib_memcpy (from, fragments_to_loopback,
 839                                sizeof (u32) * len);
 840                   n_left_from = len;
 841                   vec_reset_length (fragments_to_loopback);
 842                 }
 843               else
 844                 {
 845                   clib_memcpy (from,
 846                                fragments_to_loopback + (len -
 847                                                         VLIB_FRAME_SIZE),
 848                                sizeof (u32) * VLIB_FRAME_SIZE);
 849                   n_left_from = VLIB_FRAME_SIZE;
 850                   _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
 851                 }
 852             }
 853         }
 854
 855       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 856     }
 857
 858   vlib_node_increment_counter (vm, nat64_out2in_reass_node.index,
 859                                NAT64_OUT2IN_ERROR_OUT2IN_PACKETS,
 860                                pkts_processed);
 861
 862   nat_send_all_to_node (vm, fragments_to_drop, node,
 863                         &node->errors[NAT64_OUT2IN_ERROR_DROP_FRAGMENT],
 864                         NAT64_OUT2IN_NEXT_DROP);
 865
 866   vec_free (fragments_to_drop);
 867   vec_free (fragments_to_loopback);
 868   return frame->n_vectors;
 869 }
 870
 871 /* *INDENT-OFF* */
 872 VLIB_REGISTER_NODE (nat64_out2in_reass_node) = {
 873   .function = nat64_out2in_reass_node_fn,
 874   .name = "nat64-out2in-reass",
 875   .vector_size = sizeof (u32),
 876   .format_trace = format_nat64_out2in_reass_trace,
 877   .type = VLIB_NODE_TYPE_INTERNAL,
 878   .n_errors = ARRAY_LEN (nat64_out2in_error_strings),
 879   .error_strings = nat64_out2in_error_strings,
 880   .n_next_nodes = NAT64_OUT2IN_N_NEXT,
 881   /* edit / add dispositions here */
 882   .next_nodes = {
 883     [NAT64_OUT2IN_NEXT_DROP] = "error-drop",
 884     [NAT64_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup",
 885     [NAT64_OUT2IN_NEXT_IP4_LOOKUP] = "ip4-lookup",
 886     [NAT64_OUT2IN_NEXT_REASS] = "nat64-out2in-reass",
 887   },
 888 };
 889 /* *INDENT-ON* */
 890
 891 VLIB_NODE_FUNCTION_MULTIARCH (nat64_out2in_reass_node,
 892                               nat64_out2in_reass_node_fn);
 893
 894 typedef struct
 895 {
 896   u32 next_worker_index;
 897   u8 do_handoff;
 898 } nat64_out2in_handoff_trace_t;
 899
 900 static u8 *
 901 format_nat64_out2in_handoff_trace (u8 * s, va_list * args)
 902 {
 903   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 904   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 905   nat64_out2in_handoff_trace_t *t =
 906     va_arg (*args, nat64_out2in_handoff_trace_t *);
 907   char *m;
 908
 909   m = t->do_handoff ? "next worker" : "same worker";
 910   s = format (s, "NAT64-OUT2IN-HANDOFF: %s %d", m, t->next_worker_index);
 911
 912   return s;
 913 }
 914
 915 static inline uword
 916 nat64_out2in_handoff_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 917                               vlib_frame_t * frame)
 918 {
 919   nat64_main_t *nm = &nat64_main;
 920   vlib_thread_main_t *tm = vlib_get_thread_main ();
 921   u32 n_left_from, *from, *to_next = 0, *to_next_drop = 0;
 922   static __thread vlib_frame_queue_elt_t **handoff_queue_elt_by_worker_index;
 923   static __thread vlib_frame_queue_t **congested_handoff_queue_by_worker_index
 924     = 0;
 925   vlib_frame_queue_elt_t *hf = 0;
 926   vlib_frame_queue_t *fq;
 927   vlib_frame_t *f = 0, *d = 0;
 928   int i;
 929   u32 n_left_to_next_worker = 0, *to_next_worker = 0;
 930   u32 next_worker_index = 0;
 931   u32 current_worker_index = ~0;
 932   u32 thread_index = vlib_get_thread_index ();
 933   u32 fq_index;
 934   u32 to_node_index;
 935
 936   fq_index = nm->fq_out2in_index;
 937   to_node_index = nat64_out2in_node.index;
 938
 939   if (PREDICT_FALSE (handoff_queue_elt_by_worker_index == 0))
 940     {
 941       vec_validate (handoff_queue_elt_by_worker_index, tm->n_vlib_mains - 1);
 942
 943       vec_validate_init_empty (congested_handoff_queue_by_worker_index,
 944                                tm->n_vlib_mains - 1,
 945                                (vlib_frame_queue_t *) (~0));
 946     }
 947
 948   from = vlib_frame_vector_args (frame);
 949   n_left_from = frame->n_vectors;
 950
 951   while (n_left_from > 0)
 952     {
 953       u32 bi0;
 954       vlib_buffer_t *b0;
 955       ip4_header_t *ip0;
 956       u8 do_handoff;
 957
 958       bi0 = from[0];
 959       from += 1;
 960       n_left_from -= 1;
 961
 962       b0 = vlib_get_buffer (vm, bi0);
 963
 964       ip0 = vlib_buffer_get_current (b0);
 965
 966       next_worker_index = nat64_get_worker_out2in (ip0);
 967
 968       if (PREDICT_FALSE (next_worker_index != thread_index))
 969         {
 970           do_handoff = 1;
 971
 972           if (next_worker_index != current_worker_index)
 973             {
 974               fq =
 975                 is_vlib_frame_queue_congested (fq_index, next_worker_index,
 976                                                30,
 977                                                congested_handoff_queue_by_worker_index);
 978
 979               if (fq)
 980                 {
 981                   /* if this is 1st frame */
 982                   if (!d)
 983                     {
 984                       d = vlib_get_frame_to_node (vm, nm->error_node_index);
 985                       to_next_drop = vlib_frame_vector_args (d);
 986                     }
 987
 988                   to_next_drop[0] = bi0;
 989                   to_next_drop += 1;
 990                   d->n_vectors++;
 991                   goto trace0;
 992                 }
 993
 994               if (hf)
 995                 hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
 996
 997               hf =
 998                 vlib_get_worker_handoff_queue_elt (fq_index,
 999                                                    next_worker_index,
1000                                                    handoff_queue_elt_by_worker_index);
1001               n_left_to_next_worker = VLIB_FRAME_SIZE - hf->n_vectors;
1002               to_next_worker = &hf->buffer_index[hf->n_vectors];
1003               current_worker_index = next_worker_index;
1004             }
1005
1006           ASSERT (to_next_worker != 0);
1007
1008           /* enqueue to correct worker thread */
1009           to_next_worker[0] = bi0;
1010           to_next_worker++;
1011           n_left_to_next_worker--;
1012
1013           if (n_left_to_next_worker == 0)
1014             {
1015               hf->n_vectors = VLIB_FRAME_SIZE;
1016               vlib_put_frame_queue_elt (hf);
1017               current_worker_index = ~0;
1018               handoff_queue_elt_by_worker_index[next_worker_index] = 0;
1019               hf = 0;
1020             }
1021         }
1022       else
1023         {
1024           do_handoff = 0;
1025           /* if this is 1st frame */
1026           if (!f)
1027             {
1028               f = vlib_get_frame_to_node (vm, to_node_index);
1029               to_next = vlib_frame_vector_args (f);
1030             }
1031
1032           to_next[0] = bi0;
1033           to_next += 1;
1034           f->n_vectors++;
1035         }
1036
1037     trace0:
1038       if (PREDICT_FALSE
1039           ((node->flags & VLIB_NODE_FLAG_TRACE)
1040            && (b0->flags & VLIB_BUFFER_IS_TRACED)))
1041         {
1042           nat64_out2in_handoff_trace_t *t =
1043             vlib_add_trace (vm, node, b0, sizeof (*t));
1044           t->next_worker_index = next_worker_index;
1045           t->do_handoff = do_handoff;
1046         }
1047     }
1048
1049   if (f)
1050     vlib_put_frame_to_node (vm, to_node_index, f);
1051
1052   if (d)
1053     vlib_put_frame_to_node (vm, nm->error_node_index, d);
1054
1055   if (hf)
1056     hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
1057
1058   /* Ship frames to the worker nodes */
1059   for (i = 0; i < vec_len (handoff_queue_elt_by_worker_index); i++)
1060     {
1061       if (handoff_queue_elt_by_worker_index[i])
1062         {
1063           hf = handoff_queue_elt_by_worker_index[i];
1064           /*
1065            * It works better to let the handoff node
1066            * rate-adapt, always ship the handoff queue element.
1067            */
1068           if (1 || hf->n_vectors == hf->last_n_vectors)
1069             {
1070               vlib_put_frame_queue_elt (hf);
1071               handoff_queue_elt_by_worker_index[i] = 0;
1072             }
1073           else
1074             hf->last_n_vectors = hf->n_vectors;
1075         }
1076       congested_handoff_queue_by_worker_index[i] =
1077         (vlib_frame_queue_t *) (~0);
1078     }
1079   hf = 0;
1080   current_worker_index = ~0;
1081   return frame->n_vectors;
1082 }
1083
1084 /* *INDENT-OFF* */
1085 VLIB_REGISTER_NODE (nat64_out2in_handoff_node) = {
1086   .function = nat64_out2in_handoff_node_fn,
1087   .name = "nat64-out2in-handoff",
1088   .vector_size = sizeof (u32),
1089   .format_trace = format_nat64_out2in_handoff_trace,
1090   .type = VLIB_NODE_TYPE_INTERNAL,
1091
1092   .n_next_nodes = 1,
1093
1094   .next_nodes = {
1095     [0] = "error-drop",
1096   },
1097 };
1098 /* *INDENT-ON* */
1099
1100 VLIB_NODE_FUNCTION_MULTIARCH (nat64_out2in_handoff_node,
1101                               nat64_out2in_handoff_node_fn);
1102 /*
1103  * fd.io coding-style-patch-verification: ON
1104  *
1105  * Local Variables:
1106  * eval: (c-set-style "gnu")
1107  * End:
1108  */