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 <nat/nat_inlines.h>
  23 #include <vnet/ip/ip4_to_ip6.h>
  24 #include <vnet/fib/ip4_fib.h>
  25 #include <vnet/udp/udp.h>
  26
  27 typedef struct
  28 {
  29   u32 sw_if_index;
  30   u32 next_index;
  31 } nat64_out2in_trace_t;
  32
  33 static u8 *
  34 format_nat64_out2in_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   nat64_out2in_trace_t *t = va_arg (*args, nat64_out2in_trace_t *);
  39
  40   s =
  41     format (s, "NAT64-out2in: sw_if_index %d, next index %d", t->sw_if_index,
  42             t->next_index);
  43
  44   return s;
  45 }
  46
  47 typedef struct
  48 {
  49   u32 sw_if_index;
  50   u32 next_index;
  51   u8 cached;
  52 } nat64_out2in_reass_trace_t;
  53
  54 static u8 *
  55 format_nat64_out2in_reass_trace (u8 * s, va_list * args)
  56 {
  57   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  58   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  59   nat64_out2in_reass_trace_t *t =
  60     va_arg (*args, nat64_out2in_reass_trace_t *);
  61
  62   s =
  63     format (s, "NAT64-out2in-reass: sw_if_index %d, next index %d, status %s",
  64             t->sw_if_index, t->next_index,
  65             t->cached ? "cached" : "translated");
  66
  67   return s;
  68 }
  69
  70 vlib_node_registration_t nat64_out2in_node;
  71 vlib_node_registration_t nat64_out2in_reass_node;
  72 vlib_node_registration_t nat64_out2in_handoff_node;
  73
  74 #define foreach_nat64_out2in_error                       \
  75 _(UNSUPPORTED_PROTOCOL, "Unsupported protocol")          \
  76 _(OUT2IN_PACKETS, "Good out2in packets processed")       \
  77 _(NO_TRANSLATION, "No translation")                      \
  78 _(UNKNOWN, "unknown")                                    \
  79 _(DROP_FRAGMENT, "Drop fragment")                        \
  80 _(MAX_REASS, "Maximum reassemblies exceeded")            \
  81 _(MAX_FRAG, "Maximum fragments per reassembly exceeded")
  82
  83
  84 typedef enum
  85 {
  86 #define _(sym,str) NAT64_OUT2IN_ERROR_##sym,
  87   foreach_nat64_out2in_error
  88 #undef _
  89     NAT64_OUT2IN_N_ERROR,
  90 } nat64_out2in_error_t;
  91
  92 static char *nat64_out2in_error_strings[] = {
  93 #define _(sym,string) string,
  94   foreach_nat64_out2in_error
  95 #undef _
  96 };
  97
  98 typedef enum
  99 {
 100   NAT64_OUT2IN_NEXT_IP6_LOOKUP,
 101   NAT64_OUT2IN_NEXT_IP4_LOOKUP,
 102   NAT64_OUT2IN_NEXT_DROP,
 103   NAT64_OUT2IN_NEXT_REASS,
 104   NAT64_OUT2IN_N_NEXT,
 105 } nat64_out2in_next_t;
 106
 107 typedef struct nat64_out2in_set_ctx_t_
 108 {
 109   vlib_buffer_t *b;
 110   vlib_main_t *vm;
 111   u32 thread_index;
 112 } nat64_out2in_set_ctx_t;
 113
 114 static int
 115 nat64_out2in_tcp_udp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
 116                              void *arg)
 117 {
 118   nat64_main_t *nm = &nat64_main;
 119   nat64_out2in_set_ctx_t *ctx = arg;
 120   nat64_db_bib_entry_t *bibe;
 121   nat64_db_st_entry_t *ste;
 122   ip46_address_t saddr, daddr;
 123   ip6_address_t ip6_saddr;
 124   udp_header_t *udp = ip4_next_header (ip4);
 125   tcp_header_t *tcp = ip4_next_header (ip4);
 126   u8 proto = ip4->protocol;
 127   u16 dport = udp->dst_port;
 128   u16 sport = udp->src_port;
 129   u32 sw_if_index, fib_index;
 130   u16 *checksum;
 131   ip_csum_t csum;
 132   nat64_db_t *db = &nm->db[ctx->thread_index];
 133
 134   sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
 135   fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 136
 137   clib_memset (&saddr, 0, sizeof (saddr));
 138   saddr.ip4.as_u32 = ip4->src_address.as_u32;
 139   clib_memset (&daddr, 0, sizeof (daddr));
 140   daddr.ip4.as_u32 = ip4->dst_address.as_u32;
 141
 142   ste =
 143     nat64_db_st_entry_find (db, &daddr, &saddr, dport, sport, proto,
 144                             fib_index, 0);
 145   if (ste)
 146     {
 147       bibe = nat64_db_bib_entry_by_index (db, proto, ste->bibe_index);
 148       if (!bibe)
 149         return -1;
 150     }
 151   else
 152     {
 153       bibe = nat64_db_bib_entry_find (db, &daddr, dport, proto, fib_index, 0);
 154
 155       if (!bibe)
 156         return -1;
 157
 158       nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
 159       ste =
 160         nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, sport);
 161     }
 162
 163   ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 164   ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 165
 166   ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
 167   ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
 168   udp->dst_port = bibe->in_port;
 169
 170   if (proto == IP_PROTOCOL_UDP)
 171     checksum = &udp->checksum;
 172   else
 173     {
 174       checksum = &tcp->checksum;
 175       nat64_tcp_session_set_state (ste, tcp, 0);
 176     }
 177
 178   csum = ip_csum_sub_even (*checksum, dport);
 179   csum = ip_csum_add_even (csum, udp->dst_port);
 180   *checksum = ip_csum_fold (csum);
 181
 182   vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 183
 184   nat64_session_reset_timeout (ste, ctx->vm);
 185
 186   return 0;
 187 }
 188
 189 static int
 190 nat64_out2in_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6, void *arg)
 191 {
 192   nat64_main_t *nm = &nat64_main;
 193   nat64_out2in_set_ctx_t *ctx = arg;
 194   nat64_db_bib_entry_t *bibe;
 195   nat64_db_st_entry_t *ste;
 196   ip46_address_t saddr, daddr;
 197   ip6_address_t ip6_saddr;
 198   u32 sw_if_index, fib_index;
 199   icmp46_header_t *icmp = ip4_next_header (ip4);
 200   nat64_db_t *db = &nm->db[ctx->thread_index];
 201
 202   sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
 203   fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 204
 205   clib_memset (&saddr, 0, sizeof (saddr));
 206   saddr.ip4.as_u32 = ip4->src_address.as_u32;
 207   clib_memset (&daddr, 0, sizeof (daddr));
 208   daddr.ip4.as_u32 = ip4->dst_address.as_u32;
 209
 210   if (icmp->type == ICMP6_echo_request || icmp->type == ICMP6_echo_reply)
 211     {
 212       u16 out_id = ((u16 *) (icmp))[2];
 213       ste =
 214         nat64_db_st_entry_find (db, &daddr, &saddr, out_id, 0,
 215                                 IP_PROTOCOL_ICMP, fib_index, 0);
 216
 217       if (ste)
 218         {
 219           bibe =
 220             nat64_db_bib_entry_by_index (db, IP_PROTOCOL_ICMP,
 221                                          ste->bibe_index);
 222           if (!bibe)
 223             return -1;
 224         }
 225       else
 226         {
 227           bibe =
 228             nat64_db_bib_entry_find (db, &daddr, out_id,
 229                                      IP_PROTOCOL_ICMP, fib_index, 0);
 230           if (!bibe)
 231             return -1;
 232
 233           nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
 234           ste =
 235             nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, 0);
 236         }
 237
 238       nat64_session_reset_timeout (ste, ctx->vm);
 239
 240       ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 241       ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 242
 243       ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
 244       ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
 245       ((u16 *) (icmp))[2] = bibe->in_port;
 246
 247       vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 248     }
 249   else
 250     {
 251       ip6_header_t *inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8);
 252
 253       nat64_compose_ip6 (&ip6->src_address, &ip4->src_address,
 254                          vnet_buffer (ctx->b)->sw_if_index[VLIB_TX]);
 255       ip6->dst_address.as_u64[0] = inner_ip6->src_address.as_u64[0];
 256       ip6->dst_address.as_u64[1] = inner_ip6->src_address.as_u64[1];
 257     }
 258
 259   return 0;
 260 }
 261
 262 static int
 263 nat64_out2in_inner_icmp_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
 264                                 void *arg)
 265 {
 266   nat64_main_t *nm = &nat64_main;
 267   nat64_out2in_set_ctx_t *ctx = arg;
 268   nat64_db_bib_entry_t *bibe;
 269   nat64_db_st_entry_t *ste;
 270   ip46_address_t saddr, daddr;
 271   u32 sw_if_index, fib_index;
 272   u8 proto = ip4->protocol;
 273   nat64_db_t *db = &nm->db[ctx->thread_index];
 274
 275   sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
 276   fib_index =
 277     fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index);
 278
 279   clib_memset (&saddr, 0, sizeof (saddr));
 280   saddr.ip4.as_u32 = ip4->src_address.as_u32;
 281   clib_memset (&daddr, 0, sizeof (daddr));
 282   daddr.ip4.as_u32 = ip4->dst_address.as_u32;
 283
 284   if (proto == IP_PROTOCOL_ICMP6)
 285     {
 286       icmp46_header_t *icmp = ip4_next_header (ip4);
 287       u16 out_id = ((u16 *) (icmp))[2];
 288       proto = IP_PROTOCOL_ICMP;
 289
 290       if (!
 291           (icmp->type == ICMP6_echo_request
 292            || icmp->type == ICMP6_echo_reply))
 293         return -1;
 294
 295       ste =
 296         nat64_db_st_entry_find (db, &saddr, &daddr, out_id, 0, proto,
 297                                 fib_index, 0);
 298       if (!ste)
 299         return -1;
 300
 301       bibe = nat64_db_bib_entry_by_index (db, proto, ste->bibe_index);
 302       if (!bibe)
 303         return -1;
 304
 305       ip6->dst_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 306       ip6->dst_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 307       ip6->src_address.as_u64[0] = bibe->in_addr.as_u64[0];
 308       ip6->src_address.as_u64[1] = bibe->in_addr.as_u64[1];
 309       ((u16 *) (icmp))[2] = bibe->in_port;
 310
 311       vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 312     }
 313   else
 314     {
 315       udp_header_t *udp = ip4_next_header (ip4);
 316       tcp_header_t *tcp = ip4_next_header (ip4);
 317       u16 dport = udp->dst_port;
 318       u16 sport = udp->src_port;
 319       u16 *checksum;
 320       ip_csum_t csum;
 321
 322       ste =
 323         nat64_db_st_entry_find (db, &saddr, &daddr, sport, dport, proto,
 324                                 fib_index, 0);
 325       if (!ste)
 326         return -1;
 327
 328       bibe = nat64_db_bib_entry_by_index (db, proto, ste->bibe_index);
 329       if (!bibe)
 330         return -1;
 331
 332       nat64_compose_ip6 (&ip6->dst_address, &daddr.ip4, bibe->fib_index);
 333       ip6->src_address.as_u64[0] = bibe->in_addr.as_u64[0];
 334       ip6->src_address.as_u64[1] = bibe->in_addr.as_u64[1];
 335       udp->src_port = bibe->in_port;
 336
 337       if (proto == IP_PROTOCOL_UDP)
 338         checksum = &udp->checksum;
 339       else
 340         checksum = &tcp->checksum;
 341       if (*checksum)
 342         {
 343           csum = ip_csum_sub_even (*checksum, sport);
 344           csum = ip_csum_add_even (csum, udp->src_port);
 345           *checksum = ip_csum_fold (csum);
 346         }
 347
 348       vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 349     }
 350
 351   return 0;
 352 }
 353
 354 static int
 355 nat64_out2in_unk_proto_set_cb (ip4_header_t * ip4, ip6_header_t * ip6,
 356                                void *arg)
 357 {
 358   nat64_main_t *nm = &nat64_main;
 359   nat64_out2in_set_ctx_t *ctx = arg;
 360   nat64_db_bib_entry_t *bibe;
 361   nat64_db_st_entry_t *ste;
 362   ip46_address_t saddr, daddr;
 363   ip6_address_t ip6_saddr;
 364   u32 sw_if_index, fib_index;
 365   u8 proto = ip4->protocol;
 366   nat64_db_t *db = &nm->db[ctx->thread_index];
 367
 368   sw_if_index = vnet_buffer (ctx->b)->sw_if_index[VLIB_RX];
 369   fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 370
 371   clib_memset (&saddr, 0, sizeof (saddr));
 372   saddr.ip4.as_u32 = ip4->src_address.as_u32;
 373   clib_memset (&daddr, 0, sizeof (daddr));
 374   daddr.ip4.as_u32 = ip4->dst_address.as_u32;
 375
 376   ste =
 377     nat64_db_st_entry_find (db, &daddr, &saddr, 0, 0, proto, fib_index, 0);
 378   if (ste)
 379     {
 380       bibe = nat64_db_bib_entry_by_index (db, proto, ste->bibe_index);
 381       if (!bibe)
 382         return -1;
 383     }
 384   else
 385     {
 386       bibe = nat64_db_bib_entry_find (db, &daddr, 0, proto, fib_index, 0);
 387
 388       if (!bibe)
 389         return -1;
 390
 391       nat64_compose_ip6 (&ip6_saddr, &ip4->src_address, bibe->fib_index);
 392       ste = nat64_db_st_entry_create (db, bibe, &ip6_saddr, &saddr.ip4, 0);
 393     }
 394
 395   nat64_session_reset_timeout (ste, ctx->vm);
 396
 397   ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 398   ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 399
 400   ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
 401   ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
 402
 403   vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 404
 405   return 0;
 406 }
 407
 408 static uword
 409 nat64_out2in_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 410                       vlib_frame_t * frame)
 411 {
 412   u32 n_left_from, *from, *to_next;
 413   nat64_out2in_next_t next_index;
 414   u32 pkts_processed = 0;
 415   u32 thread_index = vm->thread_index;
 416
 417   from = vlib_frame_vector_args (frame);
 418   n_left_from = frame->n_vectors;
 419   next_index = node->cached_next_index;
 420   while (n_left_from > 0)
 421     {
 422       u32 n_left_to_next;
 423
 424       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 425
 426       while (n_left_from > 0 && n_left_to_next > 0)
 427         {
 428           u32 bi0;
 429           vlib_buffer_t *b0;
 430           u32 next0;
 431           ip4_header_t *ip40;
 432           u32 proto0;
 433           nat64_out2in_set_ctx_t ctx0;
 434           udp_header_t *udp0;
 435
 436           /* speculatively enqueue b0 to the current next frame */
 437           bi0 = from[0];
 438           to_next[0] = bi0;
 439           from += 1;
 440           to_next += 1;
 441           n_left_from -= 1;
 442           n_left_to_next -= 1;
 443
 444           b0 = vlib_get_buffer (vm, bi0);
 445           ip40 = vlib_buffer_get_current (b0);
 446
 447           ctx0.b = b0;
 448           ctx0.vm = vm;
 449           ctx0.thread_index = thread_index;
 450
 451           next0 = NAT64_OUT2IN_NEXT_IP6_LOOKUP;
 452
 453           proto0 = ip_proto_to_snat_proto (ip40->protocol);
 454
 455           if (PREDICT_FALSE (proto0 == ~0))
 456             {
 457               if (ip4_to_ip6 (b0, nat64_out2in_unk_proto_set_cb, &ctx0))
 458                 {
 459                   next0 = NAT64_OUT2IN_NEXT_DROP;
 460                   b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 461                 }
 462               goto trace0;
 463             }
 464
 465           if (PREDICT_FALSE (ip4_is_fragment (ip40)))
 466             {
 467               next0 = NAT64_OUT2IN_NEXT_REASS;
 468               goto trace0;
 469             }
 470
 471           if (proto0 == SNAT_PROTOCOL_ICMP)
 472             {
 473               if (icmp_to_icmp6
 474                   (b0, nat64_out2in_icmp_set_cb, &ctx0,
 475                    nat64_out2in_inner_icmp_set_cb, &ctx0))
 476                 {
 477                   next0 = NAT64_OUT2IN_NEXT_DROP;
 478                   b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 479                   goto trace0;
 480                 }
 481             }
 482           else
 483             {
 484               if (ip4_to_ip6_tcp_udp (b0, nat64_out2in_tcp_udp_set_cb, &ctx0))
 485                 {
 486                   udp0 = ip4_next_header (ip40);
 487                   /*
 488                    * Send DHCP packets to the ipv4 stack, or we won't
 489                    * be able to use dhcp client on the outside interface
 490                    */
 491                   if ((proto0 == SNAT_PROTOCOL_UDP)
 492                       && (udp0->dst_port ==
 493                           clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_client)))
 494                     {
 495                       next0 = NAT64_OUT2IN_NEXT_IP4_LOOKUP;
 496                       goto trace0;
 497                     }
 498                   next0 = NAT64_OUT2IN_NEXT_DROP;
 499                   b0->error = node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 500                   goto trace0;
 501                 }
 502             }
 503
 504         trace0:
 505           if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
 506                              && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 507             {
 508               nat64_out2in_trace_t *t =
 509                 vlib_add_trace (vm, node, b0, sizeof (*t));
 510               t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 511               t->next_index = next0;
 512             }
 513
 514           pkts_processed += next0 != NAT64_OUT2IN_NEXT_DROP;
 515
 516           /* verify speculative enqueue, maybe switch current next frame */
 517           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 518                                            n_left_to_next, bi0, next0);
 519         }
 520       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 521     }
 522   vlib_node_increment_counter (vm, nat64_out2in_node.index,
 523                                NAT64_OUT2IN_ERROR_OUT2IN_PACKETS,
 524                                pkts_processed);
 525   return frame->n_vectors;
 526 }
 527
 528 /* *INDENT-OFF* */
 529 VLIB_REGISTER_NODE (nat64_out2in_node) = {
 530   .function = nat64_out2in_node_fn,
 531   .name = "nat64-out2in",
 532   .vector_size = sizeof (u32),
 533   .format_trace = format_nat64_out2in_trace,
 534   .type = VLIB_NODE_TYPE_INTERNAL,
 535   .n_errors = ARRAY_LEN (nat64_out2in_error_strings),
 536   .error_strings = nat64_out2in_error_strings,
 537   .n_next_nodes = NAT64_OUT2IN_N_NEXT,
 538   /* edit / add dispositions here */
 539   .next_nodes = {
 540     [NAT64_OUT2IN_NEXT_DROP] = "error-drop",
 541     [NAT64_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup",
 542     [NAT64_OUT2IN_NEXT_IP4_LOOKUP] = "ip4-lookup",
 543     [NAT64_OUT2IN_NEXT_REASS] = "nat64-out2in-reass",
 544   },
 545 };
 546 /* *INDENT-ON* */
 547
 548 VLIB_NODE_FUNCTION_MULTIARCH (nat64_out2in_node, nat64_out2in_node_fn);
 549
 550 typedef struct nat64_out2in_frag_set_ctx_t_
 551 {
 552   vlib_main_t *vm;
 553   vlib_buffer_t *b;
 554   u32 sess_index;
 555   u32 thread_index;
 556   u8 proto;
 557   u8 first_frag;
 558 } nat64_out2in_frag_set_ctx_t;
 559
 560 static int
 561 nat64_out2in_frag_set_cb (ip4_header_t * ip4, ip6_header_t * ip6, void *arg)
 562 {
 563   nat64_main_t *nm = &nat64_main;
 564   nat64_out2in_frag_set_ctx_t *ctx = arg;
 565   nat64_db_st_entry_t *ste;
 566   nat64_db_bib_entry_t *bibe;
 567   udp_header_t *udp = ip4_next_header (ip4);
 568   ip_csum_t csum;
 569   u16 *checksum;
 570   nat64_db_t *db = &nm->db[ctx->thread_index];
 571
 572   ste = nat64_db_st_entry_by_index (db, ctx->proto, ctx->sess_index);
 573   if (!ste)
 574     return -1;
 575
 576   bibe = nat64_db_bib_entry_by_index (db, ctx->proto, ste->bibe_index);
 577   if (!bibe)
 578     return -1;
 579
 580   if (ctx->first_frag)
 581     {
 582       udp->dst_port = bibe->in_port;
 583
 584       if (ip4->protocol == IP_PROTOCOL_UDP)
 585         {
 586           checksum = &udp->checksum;
 587
 588           if (!checksum)
 589             {
 590               u16 udp_len =
 591                 clib_host_to_net_u16 (ip4->length) - sizeof (*ip4);
 592               csum = ip_incremental_checksum (0, udp, udp_len);
 593               csum =
 594                 ip_csum_with_carry (csum, clib_host_to_net_u16 (udp_len));
 595               csum =
 596                 ip_csum_with_carry (csum,
 597                                     clib_host_to_net_u16 (IP_PROTOCOL_UDP));
 598               csum = ip_csum_with_carry (csum, ste->in_r_addr.as_u64[0]);
 599               csum = ip_csum_with_carry (csum, ste->in_r_addr.as_u64[1]);
 600               csum = ip_csum_with_carry (csum, bibe->in_addr.as_u64[0]);
 601               csum = ip_csum_with_carry (csum, bibe->in_addr.as_u64[1]);
 602               *checksum = ~ip_csum_fold (csum);
 603             }
 604           else
 605             {
 606               csum = ip_csum_sub_even (*checksum, bibe->out_addr.as_u32);
 607               csum = ip_csum_sub_even (csum, ste->out_r_addr.as_u32);
 608               csum = ip_csum_sub_even (csum, bibe->out_port);
 609               csum = ip_csum_add_even (csum, ste->in_r_addr.as_u64[0]);
 610               csum = ip_csum_add_even (csum, ste->in_r_addr.as_u64[1]);
 611               csum = ip_csum_add_even (csum, bibe->in_addr.as_u64[0]);
 612               csum = ip_csum_add_even (csum, bibe->in_addr.as_u64[1]);
 613               csum = ip_csum_add_even (csum, bibe->in_port);
 614               *checksum = ip_csum_fold (csum);
 615             }
 616         }
 617       else
 618         {
 619           tcp_header_t *tcp = ip4_next_header (ip4);
 620           nat64_tcp_session_set_state (ste, tcp, 0);
 621           checksum = &tcp->checksum;
 622           csum = ip_csum_sub_even (*checksum, bibe->out_addr.as_u32);
 623           csum = ip_csum_sub_even (csum, ste->out_r_addr.as_u32);
 624           csum = ip_csum_sub_even (csum, bibe->out_port);
 625           csum = ip_csum_add_even (csum, ste->in_r_addr.as_u64[0]);
 626           csum = ip_csum_add_even (csum, ste->in_r_addr.as_u64[1]);
 627           csum = ip_csum_add_even (csum, bibe->in_addr.as_u64[0]);
 628           csum = ip_csum_add_even (csum, bibe->in_addr.as_u64[1]);
 629           csum = ip_csum_add_even (csum, bibe->in_port);
 630           *checksum = ip_csum_fold (csum);
 631         }
 632
 633     }
 634
 635   ip6->src_address.as_u64[0] = ste->in_r_addr.as_u64[0];
 636   ip6->src_address.as_u64[1] = ste->in_r_addr.as_u64[1];
 637
 638   ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0];
 639   ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1];
 640
 641   vnet_buffer (ctx->b)->sw_if_index[VLIB_TX] = bibe->fib_index;
 642
 643   nat64_session_reset_timeout (ste, ctx->vm);
 644
 645   return 0;
 646 }
 647
 648 static uword
 649 nat64_out2in_reass_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 650                             vlib_frame_t * frame)
 651 {
 652   u32 n_left_from, *from, *to_next;
 653   nat64_out2in_next_t next_index;
 654   u32 pkts_processed = 0;
 655   u32 *fragments_to_drop = 0;
 656   u32 *fragments_to_loopback = 0;
 657   nat64_main_t *nm = &nat64_main;
 658   u32 thread_index = vm->thread_index;
 659
 660   from = vlib_frame_vector_args (frame);
 661   n_left_from = frame->n_vectors;
 662   next_index = node->cached_next_index;
 663
 664   while (n_left_from > 0)
 665     {
 666       u32 n_left_to_next;
 667
 668       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 669
 670       while (n_left_from > 0 && n_left_to_next > 0)
 671         {
 672           u32 bi0;
 673           vlib_buffer_t *b0;
 674           u32 next0;
 675           ip4_header_t *ip40;
 676           u8 cached0 = 0;
 677           u32 sw_if_index0, fib_index0;
 678           udp_header_t *udp0;
 679           nat_reass_ip4_t *reass0;
 680           ip46_address_t saddr0, daddr0;
 681           nat64_db_st_entry_t *ste0;
 682           nat64_db_bib_entry_t *bibe0;
 683           ip6_address_t ip6_saddr0;
 684           nat64_out2in_frag_set_ctx_t ctx0;
 685           nat64_db_t *db = &nm->db[thread_index];
 686
 687           /* speculatively enqueue b0 to the current next frame */
 688           bi0 = from[0];
 689           to_next[0] = bi0;
 690           from += 1;
 691           to_next += 1;
 692           n_left_from -= 1;
 693           n_left_to_next -= 1;
 694
 695           b0 = vlib_get_buffer (vm, bi0);
 696           next0 = NAT64_OUT2IN_NEXT_IP6_LOOKUP;
 697
 698           sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
 699           fib_index0 =
 700             fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 701                                                  sw_if_index0);
 702
 703           ctx0.thread_index = thread_index;
 704
 705           if (PREDICT_FALSE (nat_reass_is_drop_frag (1)))
 706             {
 707               next0 = NAT64_OUT2IN_NEXT_DROP;
 708               b0->error = node->errors[NAT64_OUT2IN_ERROR_DROP_FRAGMENT];
 709               goto trace0;
 710             }
 711
 712           ip40 = vlib_buffer_get_current (b0);
 713
 714           if (PREDICT_FALSE (!(ip40->protocol == IP_PROTOCOL_TCP
 715                                || ip40->protocol == IP_PROTOCOL_UDP)))
 716             {
 717               next0 = NAT64_OUT2IN_NEXT_DROP;
 718               b0->error = node->errors[NAT64_OUT2IN_ERROR_DROP_FRAGMENT];
 719               goto trace0;
 720             }
 721
 722           udp0 = ip4_next_header (ip40);
 723
 724           reass0 = nat_ip4_reass_find_or_create (ip40->src_address,
 725                                                  ip40->dst_address,
 726                                                  ip40->fragment_id,
 727                                                  ip40->protocol,
 728                                                  1, &fragments_to_drop);
 729
 730           if (PREDICT_FALSE (!reass0))
 731             {
 732               next0 = NAT64_OUT2IN_NEXT_DROP;
 733               b0->error = node->errors[NAT64_OUT2IN_ERROR_MAX_REASS];
 734               goto trace0;
 735             }
 736
 737           if (PREDICT_FALSE (ip4_is_first_fragment (ip40)))
 738             {
 739               ctx0.first_frag = 1;
 740
 741               clib_memset (&saddr0, 0, sizeof (saddr0));
 742               saddr0.ip4.as_u32 = ip40->src_address.as_u32;
 743               clib_memset (&daddr0, 0, sizeof (daddr0));
 744               daddr0.ip4.as_u32 = ip40->dst_address.as_u32;
 745
 746               ste0 =
 747                 nat64_db_st_entry_find (db, &daddr0, &saddr0,
 748                                         udp0->dst_port, udp0->src_port,
 749                                         ip40->protocol, fib_index0, 0);
 750               if (!ste0)
 751                 {
 752                   bibe0 =
 753                     nat64_db_bib_entry_find (db, &daddr0, udp0->dst_port,
 754                                              ip40->protocol, fib_index0, 0);
 755                   if (!bibe0)
 756                     {
 757                       next0 = NAT64_OUT2IN_NEXT_DROP;
 758                       b0->error =
 759                         node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 760                       goto trace0;
 761                     }
 762
 763                   nat64_compose_ip6 (&ip6_saddr0, &ip40->src_address,
 764                                      bibe0->fib_index);
 765                   ste0 =
 766                     nat64_db_st_entry_create (db, bibe0, &ip6_saddr0,
 767                                               &saddr0.ip4, udp0->src_port);
 768
 769                   if (!ste0)
 770                     {
 771                       next0 = NAT64_OUT2IN_NEXT_DROP;
 772                       b0->error =
 773                         node->errors[NAT64_OUT2IN_ERROR_NO_TRANSLATION];
 774                       goto trace0;
 775                     }
 776                 }
 777               reass0->sess_index = nat64_db_st_entry_get_index (db, ste0);
 778               reass0->thread_index = thread_index;
 779
 780               nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
 781             }
 782           else
 783             {
 784               ctx0.first_frag = 0;
 785
 786               if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
 787                 {
 788                   if (nat_ip4_reass_add_fragment
 789                       (reass0, bi0, &fragments_to_drop))
 790                     {
 791                       b0->error = node->errors[NAT64_OUT2IN_ERROR_MAX_FRAG];
 792                       next0 = NAT64_OUT2IN_NEXT_DROP;
 793                       goto trace0;
 794                     }
 795                   cached0 = 1;
 796                   goto trace0;
 797                 }
 798             }
 799
 800           ctx0.sess_index = reass0->sess_index;
 801           ctx0.proto = ip40->protocol;
 802           ctx0.vm = vm;
 803           ctx0.b = b0;
 804
 805           if (ip4_to_ip6_fragmented (b0, nat64_out2in_frag_set_cb, &ctx0))
 806             {
 807               next0 = NAT64_OUT2IN_NEXT_DROP;
 808               b0->error = node->errors[NAT64_OUT2IN_ERROR_UNKNOWN];
 809               goto trace0;
 810             }
 811
 812         trace0:
 813           if (PREDICT_FALSE
 814               ((node->flags & VLIB_NODE_FLAG_TRACE)
 815                && (b0->flags & VLIB_BUFFER_IS_TRACED)))
 816             {
 817               nat64_out2in_reass_trace_t *t =
 818                 vlib_add_trace (vm, node, b0, sizeof (*t));
 819               t->cached = cached0;
 820               t->sw_if_index = sw_if_index0;
 821               t->next_index = next0;
 822             }
 823
 824           if (cached0)
 825             {
 826               n_left_to_next++;
 827               to_next--;
 828             }
 829           else
 830             {
 831               pkts_processed += next0 != NAT64_OUT2IN_NEXT_DROP;
 832
 833               /* verify speculative enqueue, maybe switch current next frame */
 834               vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 835                                                to_next, n_left_to_next,
 836                                                bi0, next0);
 837             }
 838
 839           if (n_left_from == 0 && vec_len (fragments_to_loopback))
 840             {
 841               from = vlib_frame_vector_args (frame);
 842               u32 len = vec_len (fragments_to_loopback);
 843               if (len <= VLIB_FRAME_SIZE)
 844                 {
 845                   clib_memcpy (from, fragments_to_loopback,
 846                                sizeof (u32) * len);
 847                   n_left_from = len;
 848                   vec_reset_length (fragments_to_loopback);
 849                 }
 850               else
 851                 {
 852                   clib_memcpy (from,
 853                                fragments_to_loopback + (len -
 854                                                         VLIB_FRAME_SIZE),
 855                                sizeof (u32) * VLIB_FRAME_SIZE);
 856                   n_left_from = VLIB_FRAME_SIZE;
 857                   _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
 858                 }
 859             }
 860         }
 861
 862       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 863     }
 864
 865   vlib_node_increment_counter (vm, nat64_out2in_reass_node.index,
 866                                NAT64_OUT2IN_ERROR_OUT2IN_PACKETS,
 867                                pkts_processed);
 868
 869   nat_send_all_to_node (vm, fragments_to_drop, node,
 870                         &node->errors[NAT64_OUT2IN_ERROR_DROP_FRAGMENT],
 871                         NAT64_OUT2IN_NEXT_DROP);
 872
 873   vec_free (fragments_to_drop);
 874   vec_free (fragments_to_loopback);
 875   return frame->n_vectors;
 876 }
 877
 878 /* *INDENT-OFF* */
 879 VLIB_REGISTER_NODE (nat64_out2in_reass_node) = {
 880   .function = nat64_out2in_reass_node_fn,
 881   .name = "nat64-out2in-reass",
 882   .vector_size = sizeof (u32),
 883   .format_trace = format_nat64_out2in_reass_trace,
 884   .type = VLIB_NODE_TYPE_INTERNAL,
 885   .n_errors = ARRAY_LEN (nat64_out2in_error_strings),
 886   .error_strings = nat64_out2in_error_strings,
 887   .n_next_nodes = NAT64_OUT2IN_N_NEXT,
 888   /* edit / add dispositions here */
 889   .next_nodes = {
 890     [NAT64_OUT2IN_NEXT_DROP] = "error-drop",
 891     [NAT64_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup",
 892     [NAT64_OUT2IN_NEXT_IP4_LOOKUP] = "ip4-lookup",
 893     [NAT64_OUT2IN_NEXT_REASS] = "nat64-out2in-reass",
 894   },
 895 };
 896 /* *INDENT-ON* */
 897
 898 VLIB_NODE_FUNCTION_MULTIARCH (nat64_out2in_reass_node,
 899                               nat64_out2in_reass_node_fn);
 900
 901 #define foreach_nat64_out2in_handoff_error                       \
 902 _(CONGESTION_DROP, "congestion drop")
 903
 904 typedef enum
 905 {
 906 #define _(sym,str) NAT64_OUT2IN_HANDOFF_ERROR_##sym,
 907   foreach_nat64_out2in_handoff_error
 908 #undef _
 909     NAT64_OUT2IN_HANDOFF_N_ERROR,
 910 } nat64_out2in_handoff_error_t;
 911
 912 static char *nat64_out2in_handoff_error_strings[] = {
 913 #define _(sym,string) string,
 914   foreach_nat64_out2in_handoff_error
 915 #undef _
 916 };
 917
 918 typedef struct
 919 {
 920   u32 next_worker_index;
 921 } nat64_out2in_handoff_trace_t;
 922
 923 static u8 *
 924 format_nat64_out2in_handoff_trace (u8 * s, va_list * args)
 925 {
 926   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
 927   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
 928   nat64_out2in_handoff_trace_t *t =
 929     va_arg (*args, nat64_out2in_handoff_trace_t *);
 930
 931   s =
 932     format (s, "NAT64-OUT2IN-HANDOFF: next-worker %d", t->next_worker_index);
 933
 934   return s;
 935 }
 936
 937 static inline uword
 938 nat64_out2in_handoff_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 939                               vlib_frame_t * frame)
 940 {
 941   nat64_main_t *nm = &nat64_main;
 942   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
 943   u32 n_enq, n_left_from, *from;
 944   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
 945   u32 fq_index;
 946
 947   from = vlib_frame_vector_args (frame);
 948   n_left_from = frame->n_vectors;
 949   vlib_get_buffers (vm, from, bufs, n_left_from);
 950
 951   b = bufs;
 952   ti = thread_indices;
 953
 954   fq_index = nm->fq_out2in_index;
 955
 956   while (n_left_from > 0)
 957     {
 958       ip4_header_t *ip0;
 959
 960       ip0 = vlib_buffer_get_current (b[0]);
 961       ti[0] = nat64_get_worker_out2in (ip0);
 962
 963       if (PREDICT_FALSE
 964           ((node->flags & VLIB_NODE_FLAG_TRACE)
 965            && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
 966         {
 967           nat64_out2in_handoff_trace_t *t =
 968             vlib_add_trace (vm, node, b[0], sizeof (*t));
 969           t->next_worker_index = ti[0];
 970         }
 971
 972       n_left_from -= 1;
 973       ti += 1;
 974       b += 1;
 975     }
 976
 977   n_enq =
 978     vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
 979                                    frame->n_vectors, 1);
 980
 981   if (n_enq < frame->n_vectors)
 982     vlib_node_increment_counter (vm, node->node_index,
 983                                  NAT64_OUT2IN_HANDOFF_ERROR_CONGESTION_DROP,
 984                                  frame->n_vectors - n_enq);
 985   return frame->n_vectors;
 986 }
 987
 988 /* *INDENT-OFF* */
 989 VLIB_REGISTER_NODE (nat64_out2in_handoff_node) = {
 990   .function = nat64_out2in_handoff_node_fn,
 991   .name = "nat64-out2in-handoff",
 992   .vector_size = sizeof (u32),
 993   .format_trace = format_nat64_out2in_handoff_trace,
 994   .type = VLIB_NODE_TYPE_INTERNAL,
 995   .n_errors = ARRAY_LEN(nat64_out2in_handoff_error_strings),
 996   .error_strings = nat64_out2in_handoff_error_strings,
 997
 998   .n_next_nodes = 1,
 999
1000   .next_nodes = {
1001     [0] = "error-drop",
1002   },
1003 };
1004 /* *INDENT-ON* */
1005
1006 VLIB_NODE_FUNCTION_MULTIARCH (nat64_out2in_handoff_node,
1007                               nat64_out2in_handoff_node_fn);
1008 /*
1009  * fd.io coding-style-patch-verification: ON
1010  *
1011  * Local Variables:
1012  * eval: (c-set-style "gnu")
1013  * End:
1014  */