vnet/vnet/map/ip4_map.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 /*
  16  * Defines used for testing various optimisation schemes
  17  */
  18 #define MAP_ENCAP_DUAL 0
  19
  20 #include "map.h"
  21 #include "../ip/ip_frag.h"
  22
  23 vlib_node_registration_t ip4_map_reass_node;
  24
  25 enum ip4_map_next_e {
  26   IP4_MAP_NEXT_IP6_LOOKUP,
  27 #ifdef MAP_SKIP_IP6_LOOKUP
  28   IP4_MAP_NEXT_IP6_REWRITE,
  29 #endif
  30   IP4_MAP_NEXT_FRAGMENT,
  31   IP4_MAP_NEXT_REASS,
  32   IP4_MAP_NEXT_DROP,
  33   IP4_MAP_N_NEXT,
  34 };
  35
  36 enum ip4_map_reass_next_t {
  37   IP4_MAP_REASS_NEXT_IP6_LOOKUP,
  38   IP4_MAP_REASS_NEXT_IP4_FRAGMENT,
  39   IP4_MAP_REASS_NEXT_DROP,
  40   IP4_MAP_REASS_N_NEXT,
  41 };
  42
  43 typedef struct {
  44   u32 map_domain_index;
  45   u16 port;
  46   u8 cached;
  47 } map_ip4_map_reass_trace_t;
  48
  49 u8 *
  50 format_ip4_map_reass_trace (u8 *s, va_list *args)
  51 {
  52   CLIB_UNUSED(vlib_main_t *vm) = va_arg (*args, vlib_main_t *);
  53   CLIB_UNUSED(vlib_node_t *node) = va_arg (*args, vlib_node_t *);
  54   map_ip4_map_reass_trace_t *t = va_arg (*args, map_ip4_map_reass_trace_t *);
  55   return format(s, "MAP domain index: %d L4 port: %u Status: %s", t->map_domain_index,
  56                 t->port, t->cached?"cached":"forwarded");
  57 }
  58
  59 /*
  60  * ip4_map_get_port
  61  */
  62 u16
  63 ip4_map_get_port (ip4_header_t *ip, map_dir_e dir)
  64 {
  65   /* Find port information */
  66   if (PREDICT_TRUE((ip->protocol == IP_PROTOCOL_TCP) ||
  67                    (ip->protocol == IP_PROTOCOL_UDP))) {
  68     udp_header_t *udp = (void *)(ip + 1);
  69     return (dir == MAP_SENDER ? udp->src_port : udp->dst_port);
  70   } else if (ip->protocol == IP_PROTOCOL_ICMP) {
  71     /*
  72      * 1) ICMP Echo request or Echo reply
  73      * 2) ICMP Error with inner packet being UDP or TCP
  74      * 3) ICMP Error with inner packet being ICMP Echo request or Echo reply
  75      */
  76     icmp46_header_t *icmp = (void *)(ip + 1);
  77     if (icmp->type == ICMP4_echo_request || icmp->type == ICMP4_echo_reply) {
  78       return *((u16 *)(icmp + 1));
  79     } else if (clib_net_to_host_u16(ip->length) >= 64) { // IP + ICMP + IP + L4 header
  80       ip4_header_t *icmp_ip = (ip4_header_t *)(icmp + 2);
  81       if (PREDICT_TRUE((icmp_ip->protocol == IP_PROTOCOL_TCP) ||
  82                        (icmp_ip->protocol == IP_PROTOCOL_UDP))) {
  83         udp_header_t *udp = (void *)(icmp_ip + 1);
  84         return (dir == MAP_SENDER ? udp->dst_port : udp->src_port);
  85       } else if (icmp_ip->protocol == IP_PROTOCOL_ICMP) {
  86         icmp46_header_t *inner_icmp = (void *)(icmp_ip + 1);
  87         if (inner_icmp->type == ICMP4_echo_request || inner_icmp->type == ICMP4_echo_reply)
  88           return (*((u16 *)(inner_icmp + 1)));
  89       }
  90     }
  91   }
  92   return (0);
  93 }
  94
  95 static_always_inline u16
  96 ip4_map_port_and_security_check (map_domain_t *d, ip4_header_t *ip, u32 *next, u8 *error)
  97 {
  98   u16 port = 0;
  99
 100   if (d->psid_length > 0) {
 101     if (!ip4_is_fragment(ip)) {
 102       if (PREDICT_FALSE((ip->ip_version_and_header_length != 0x45) || clib_host_to_net_u16(ip->length) < 28)) {
 103         return 0;
 104       }
 105       port = ip4_map_get_port(ip, MAP_RECEIVER);
 106       if (port) {
 107         /* Verify that port is not among the well-known ports */
 108         if ((d->psid_offset > 0) && (clib_net_to_host_u16(port) < (0x1 << (16 - d->psid_offset)))) {
 109           *error = MAP_ERROR_ENCAP_SEC_CHECK;
 110         } else {
 111           return (port);
 112         }
 113       } else {
 114         *error = MAP_ERROR_BAD_PROTOCOL;
 115       }
 116     } else {
 117       *next = IP4_MAP_NEXT_REASS;
 118     }
 119   }
 120   return (0);
 121 }
 122
 123 /*
 124  * ip4_map_vtcfl
 125  */
 126 static_always_inline u32
 127 ip4_map_vtcfl (ip4_header_t *ip4, vlib_buffer_t *p)
 128 {
 129   map_main_t *mm = &map_main;
 130   u8 tc = mm->tc_copy ? ip4->tos : mm->tc;
 131   u32 vtcfl = 0x6 << 28;
 132   vtcfl |= tc << 20;
 133   vtcfl |= vnet_buffer(p)->ip.flow_hash & 0x000fffff;
 134
 135   return (clib_host_to_net_u32(vtcfl));
 136 }
 137
 138 static_always_inline bool
 139 ip4_map_ip6_lookup_bypass (vlib_buffer_t *p0, ip4_header_t *ip)
 140 {
 141 #ifdef MAP_SKIP_IP6_LOOKUP
 142   map_main_t *mm = &map_main;
 143   u32 adj_index0 = mm->adj6_index;
 144   if (adj_index0 > 0) {
 145     ip_lookup_main_t *lm6 = &ip6_main.lookup_main;
 146     ip_adjacency_t *adj = ip_get_adjacency(lm6, mm->adj6_index);
 147     if (adj->n_adj > 1) {
 148       u32 hash_c0 = ip4_compute_flow_hash(ip, IP_FLOW_HASH_DEFAULT);
 149       adj_index0 += (hash_c0 & (adj->n_adj - 1));
 150     }
 151     vnet_buffer(p0)->ip.adj_index[VLIB_TX] = adj_index0;
 152     return (true);
 153   }
 154 #endif
 155   return (false);
 156 }
 157
 158 /*
 159  * ip4_map
 160  */
 161 static uword
 162 ip4_map (vlib_main_t *vm,
 163          vlib_node_runtime_t *node,
 164          vlib_frame_t *frame)
 165 {
 166   u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
 167   vlib_node_runtime_t *error_node = vlib_node_get_runtime(vm, ip4_map_node.index);
 168   from = vlib_frame_vector_args(frame);
 169   n_left_from = frame->n_vectors;
 170   next_index = node->cached_next_index;
 171   map_main_t *mm = &map_main;
 172   vlib_combined_counter_main_t *cm = mm->domain_counters;
 173   u32 cpu_index = os_get_cpu_number();
 174
 175   while (n_left_from > 0) {
 176     vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
 177
 178     /* Dual loop */
 179     while (n_left_from >= 4 && n_left_to_next >= 2) {
 180       u32 pi0, pi1;
 181       vlib_buffer_t *p0, *p1;
 182       map_domain_t *d0, *d1;
 183       u8 error0 = MAP_ERROR_NONE, error1 = MAP_ERROR_NONE;
 184       ip4_header_t *ip40, *ip41;
 185       u16 port0 = 0, port1 = 0;
 186       ip6_header_t *ip6h0, *ip6h1;
 187       u32 map_domain_index0 = ~0, map_domain_index1 = ~0;
 188       u32 next0 = IP4_MAP_NEXT_IP6_LOOKUP, next1 = IP4_MAP_NEXT_IP6_LOOKUP;
 189
 190       /* Prefetch next iteration. */
 191       {
 192         vlib_buffer_t *p2, *p3;
 193
 194         p2 = vlib_get_buffer(vm, from[2]);
 195         p3 = vlib_get_buffer(vm, from[3]);
 196
 197         vlib_prefetch_buffer_header(p2, STORE);
 198         vlib_prefetch_buffer_header(p3, STORE);
 199         /* IPv4 + 8 = 28. possibly plus -40 */
 200         CLIB_PREFETCH (p2->data-40, 68, STORE);
 201         CLIB_PREFETCH (p3->data-40, 68, STORE);
 202       }
 203
 204       pi0 = to_next[0] = from[0];
 205       pi1 = to_next[1] = from[1];
 206       from += 2;
 207       n_left_from -= 2;
 208       to_next +=2;
 209       n_left_to_next -= 2;
 210
 211       p0 = vlib_get_buffer(vm, pi0);
 212       p1 = vlib_get_buffer(vm, pi1);
 213       ip40 = vlib_buffer_get_current(p0);
 214       ip41 = vlib_buffer_get_current(p1);
 215       p0->current_length = clib_net_to_host_u16(ip40->length);
 216       p1->current_length = clib_net_to_host_u16(ip41->length);
 217       d0 = ip4_map_get_domain(vnet_buffer(p0)->ip.adj_index[VLIB_TX], &map_domain_index0);
 218       d1 = ip4_map_get_domain(vnet_buffer(p1)->ip.adj_index[VLIB_TX], &map_domain_index1);
 219       ASSERT(d0);
 220       ASSERT(d1);
 221
 222       /*
 223        * Shared IPv4 address
 224        */
 225       port0 = ip4_map_port_and_security_check(d0, ip40, &next0, &error0);
 226       port1 = ip4_map_port_and_security_check(d1, ip41, &next1, &error1);
 227
 228       /* MAP calc */
 229       u32 da40 = clib_net_to_host_u32(ip40->dst_address.as_u32);
 230       u32 da41 = clib_net_to_host_u32(ip41->dst_address.as_u32);
 231       u16 dp40 = clib_net_to_host_u16(port0);
 232       u16 dp41 = clib_net_to_host_u16(port1);
 233       u64 dal60 = map_get_pfx(d0, da40, dp40);
 234       u64 dal61 = map_get_pfx(d1, da41, dp41);
 235       u64 dar60 = map_get_sfx(d0, da40, dp40);
 236       u64 dar61 = map_get_sfx(d1, da41, dp41);
 237       if (dal60 == 0 && dar60 == 0) error0 = MAP_ERROR_UNKNOWN;
 238       if (dal61 == 0 && dar61 == 0) error1 = MAP_ERROR_UNKNOWN;
 239
 240       /* construct ipv6 header */
 241       vlib_buffer_advance(p0, - sizeof(ip6_header_t));
 242       vlib_buffer_advance(p1, - sizeof(ip6_header_t));
 243       ip6h0 = vlib_buffer_get_current(p0);
 244       ip6h1 = vlib_buffer_get_current(p1);
 245       vnet_buffer(p0)->sw_if_index[VLIB_TX] = (u32)~0;
 246       vnet_buffer(p1)->sw_if_index[VLIB_TX] = (u32)~0;
 247
 248       ip6h0->ip_version_traffic_class_and_flow_label = ip4_map_vtcfl(ip40, p0);
 249       ip6h1->ip_version_traffic_class_and_flow_label = ip4_map_vtcfl(ip41, p1);
 250       ip6h0->payload_length = ip40->length;
 251       ip6h1->payload_length = ip41->length;
 252       ip6h0->protocol = IP_PROTOCOL_IP_IN_IP;
 253       ip6h1->protocol = IP_PROTOCOL_IP_IN_IP;
 254       ip6h0->hop_limit = 0x40;
 255       ip6h1->hop_limit = 0x40;
 256       ip6h0->src_address = d0->ip6_src;
 257       ip6h1->src_address = d1->ip6_src;
 258       ip6h0->dst_address.as_u64[0] = clib_host_to_net_u64(dal60);
 259       ip6h0->dst_address.as_u64[1] = clib_host_to_net_u64(dar60);
 260       ip6h1->dst_address.as_u64[0] = clib_host_to_net_u64(dal61);
 261       ip6h1->dst_address.as_u64[1] = clib_host_to_net_u64(dar61);
 262
 263       /*
 264        * Determine next node. Can be one of:
 265        * ip6-lookup, ip6-rewrite, ip4-fragment, ip4-virtreass, error-drop
 266        */
 267       if (PREDICT_TRUE(error0 == MAP_ERROR_NONE)) {
 268         if (PREDICT_FALSE(d0->mtu && (clib_net_to_host_u16(ip6h0->payload_length) + sizeof(*ip6h0) > d0->mtu))) {
 269           vnet_buffer(p0)->ip_frag.header_offset = sizeof(*ip6h0);
 270           vnet_buffer(p0)->ip_frag.next_index = IP4_FRAG_NEXT_IP6_LOOKUP;
 271           vnet_buffer(p0)->ip_frag.mtu = d0->mtu;
 272           vnet_buffer(p0)->ip_frag.flags = IP_FRAG_FLAG_IP6_HEADER;
 273           next0 = IP4_MAP_NEXT_FRAGMENT;
 274         } else {
 275           next0 = ip4_map_ip6_lookup_bypass(p0, ip40) ? IP4_MAP_NEXT_IP6_REWRITE : next0;
 276           vlib_increment_combined_counter(cm + MAP_DOMAIN_COUNTER_TX, cpu_index, map_domain_index0, 1,
 277                                           clib_net_to_host_u16(ip6h0->payload_length) + 40);
 278         }
 279       } else {
 280         next0 = IP4_MAP_NEXT_DROP;
 281       }
 282
 283       /*
 284        * Determine next node. Can be one of:
 285        * ip6-lookup, ip6-rewrite, ip4-fragment, ip4-virtreass, error-drop
 286        */
 287       if (PREDICT_TRUE(error1 == MAP_ERROR_NONE)) {
 288         if (PREDICT_FALSE(d1->mtu && (clib_net_to_host_u16(ip6h1->payload_length) + sizeof(*ip6h1) > d1->mtu))) {
 289           vnet_buffer(p1)->ip_frag.header_offset = sizeof(*ip6h1);
 290           vnet_buffer(p1)->ip_frag.next_index = IP4_FRAG_NEXT_IP6_LOOKUP;
 291           vnet_buffer(p1)->ip_frag.mtu = d1->mtu;
 292           vnet_buffer(p1)->ip_frag.flags = IP_FRAG_FLAG_IP6_HEADER;
 293           next1 = IP4_MAP_NEXT_FRAGMENT;
 294         } else {
 295           next1 = ip4_map_ip6_lookup_bypass(p1, ip41) ? IP4_MAP_NEXT_IP6_REWRITE : next1;
 296           vlib_increment_combined_counter(cm + MAP_DOMAIN_COUNTER_TX, cpu_index, map_domain_index1, 1,
 297                                           clib_net_to_host_u16(ip6h1->payload_length) + 40);
 298         }
 299       } else {
 300         next1 = IP4_MAP_NEXT_DROP;
 301       }
 302
 303       if (PREDICT_FALSE(p0->flags & VLIB_BUFFER_IS_TRACED)) {
 304         map_trace_t *tr = vlib_add_trace(vm, node, p0, sizeof(*tr));
 305         tr->map_domain_index = map_domain_index0;
 306         tr->port = port0;
 307       }
 308       if (PREDICT_FALSE(p1->flags & VLIB_BUFFER_IS_TRACED)) {
 309         map_trace_t *tr = vlib_add_trace(vm, node, p1, sizeof(*tr));
 310         tr->map_domain_index = map_domain_index1;
 311         tr->port = port1;
 312       }
 313
 314       p0->error = error_node->errors[error0];
 315       p1->error = error_node->errors[error1];
 316
 317       vlib_validate_buffer_enqueue_x2(vm, node, next_index, to_next, n_left_to_next, pi0, pi1, next0, next1);
 318     }
 319
 320     while (n_left_from > 0 && n_left_to_next > 0) {
 321       u32 pi0;
 322       vlib_buffer_t *p0;
 323       map_domain_t *d0;
 324       u8 error0 = MAP_ERROR_NONE;
 325       ip4_header_t *ip40;
 326       u16 port0 = 0;
 327       ip6_header_t *ip6h0;
 328       u32 next0 = IP4_MAP_NEXT_IP6_LOOKUP;
 329       u32 map_domain_index0 = ~0;
 330
 331       pi0 = to_next[0] = from[0];
 332       from += 1;
 333       n_left_from -= 1;
 334       to_next +=1;
 335       n_left_to_next -= 1;
 336
 337       p0 = vlib_get_buffer(vm, pi0);
 338       ip40 = vlib_buffer_get_current(p0);
 339       p0->current_length = clib_net_to_host_u16(ip40->length);
 340       d0 = ip4_map_get_domain(vnet_buffer(p0)->ip.adj_index[VLIB_TX], &map_domain_index0);
 341       ASSERT(d0);
 342
 343       /*
 344        * Shared IPv4 address
 345        */
 346       port0 = ip4_map_port_and_security_check(d0, ip40, &next0, &error0);
 347
 348       /* MAP calc */
 349       u32 da40 = clib_net_to_host_u32(ip40->dst_address.as_u32);
 350       u16 dp40 = clib_net_to_host_u16(port0);
 351       u64 dal60 = map_get_pfx(d0, da40, dp40);
 352       u64 dar60 = map_get_sfx(d0, da40, dp40);
 353       if (dal60 == 0 && dar60 == 0 && error0 == MAP_ERROR_NONE) error0 = MAP_ERROR_UNKNOWN;
 354
 355       /* construct ipv6 header */
 356       vlib_buffer_advance(p0, - (sizeof(ip6_header_t)));
 357       ip6h0 = vlib_buffer_get_current(p0);
 358       vnet_buffer(p0)->sw_if_index[VLIB_TX] = (u32)~0;
 359
 360       ip6h0->ip_version_traffic_class_and_flow_label = ip4_map_vtcfl(ip40, p0);
 361       ip6h0->payload_length = ip40->length;
 362       ip6h0->protocol = IP_PROTOCOL_IP_IN_IP;
 363       ip6h0->hop_limit = 0x40;
 364       ip6h0->src_address = d0->ip6_src;
 365       ip6h0->dst_address.as_u64[0] = clib_host_to_net_u64(dal60);
 366       ip6h0->dst_address.as_u64[1] = clib_host_to_net_u64(dar60);
 367
 368       /*
 369        * Determine next node. Can be one of:
 370        * ip6-lookup, ip6-rewrite, ip4-fragment, ip4-virtreass, error-drop
 371        */
 372       if (PREDICT_TRUE(error0 == MAP_ERROR_NONE)) {
 373         if (PREDICT_FALSE(d0->mtu && (clib_net_to_host_u16(ip6h0->payload_length) + sizeof(*ip6h0) > d0->mtu))) {
 374           vnet_buffer(p0)->ip_frag.header_offset = sizeof(*ip6h0);
 375           vnet_buffer(p0)->ip_frag.next_index = IP4_FRAG_NEXT_IP6_LOOKUP;
 376           vnet_buffer(p0)->ip_frag.mtu = d0->mtu;
 377           vnet_buffer(p0)->ip_frag.flags = IP_FRAG_FLAG_IP6_HEADER;
 378           next0 = IP4_MAP_NEXT_FRAGMENT;
 379         } else {
 380           next0 = ip4_map_ip6_lookup_bypass(p0, ip40) ? IP4_MAP_NEXT_IP6_REWRITE : next0;
 381           vlib_increment_combined_counter(cm + MAP_DOMAIN_COUNTER_TX, cpu_index, map_domain_index0, 1,
 382                                           clib_net_to_host_u16(ip6h0->payload_length) + 40);
 383         }
 384       } else {
 385         next0 = IP4_MAP_NEXT_DROP;
 386       }
 387
 388       if (PREDICT_FALSE(p0->flags & VLIB_BUFFER_IS_TRACED)) {
 389         map_trace_t *tr = vlib_add_trace(vm, node, p0, sizeof(*tr));
 390         tr->map_domain_index = map_domain_index0;
 391         tr->port = port0;
 392       }
 393
 394       p0->error = error_node->errors[error0];
 395       vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, pi0, next0);
 396     }
 397     vlib_put_next_frame(vm, node, next_index, n_left_to_next);
 398   }
 399
 400   return frame->n_vectors;
 401 }
 402
 403 /*
 404  * ip4_map_reass
 405  */
 406 static uword
 407 ip4_map_reass (vlib_main_t *vm,
 408                vlib_node_runtime_t *node,
 409                vlib_frame_t *frame)
 410 {
 411   u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
 412   vlib_node_runtime_t *error_node = vlib_node_get_runtime(vm, ip4_map_reass_node.index);
 413   from = vlib_frame_vector_args(frame);
 414   n_left_from = frame->n_vectors;
 415   next_index = node->cached_next_index;
 416   map_main_t *mm = &map_main;
 417   vlib_combined_counter_main_t *cm = mm->domain_counters;
 418   u32 cpu_index = os_get_cpu_number();
 419   u32 *fragments_to_drop = NULL;
 420   u32 *fragments_to_loopback = NULL;
 421
 422   while (n_left_from > 0) {
 423     vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
 424
 425     while (n_left_from > 0 && n_left_to_next > 0) {
 426       u32 pi0;
 427       vlib_buffer_t *p0;
 428       map_domain_t *d0;
 429       u8 error0 = MAP_ERROR_NONE;
 430       ip4_header_t *ip40;
 431       i32 port0 = 0;
 432       ip6_header_t *ip60;
 433       u32 next0 = IP4_MAP_REASS_NEXT_IP6_LOOKUP;
 434       u32 map_domain_index0;
 435       u8 cached = 0;
 436
 437       pi0 = to_next[0] = from[0];
 438       from += 1;
 439       n_left_from -= 1;
 440       to_next +=1;
 441       n_left_to_next -= 1;
 442
 443       p0 = vlib_get_buffer(vm, pi0);
 444       ip60 = vlib_buffer_get_current(p0);
 445       ip40 = (ip4_header_t *)(ip60 + 1);
 446       d0 = ip4_map_get_domain(vnet_buffer(p0)->ip.adj_index[VLIB_TX], &map_domain_index0);
 447
 448       map_ip4_reass_lock();
 449       map_ip4_reass_t *r = map_ip4_reass_get(ip40->src_address.as_u32, ip40->dst_address.as_u32,
 450                                              ip40->fragment_id, ip40->protocol, &fragments_to_drop);
 451       if (PREDICT_FALSE(!r)) {
 452         // Could not create a caching entry
 453         error0 = MAP_ERROR_FRAGMENT_MEMORY;
 454       } else if (PREDICT_TRUE(ip4_get_fragment_offset(ip40))) {
 455         if (r->port >= 0) {
 456           // We know the port already
 457           port0 = r->port;
 458         } else if (map_ip4_reass_add_fragment(r, pi0)) {
 459           // Not enough space for caching
 460           error0 = MAP_ERROR_FRAGMENT_MEMORY;
 461           map_ip4_reass_free(r, &fragments_to_drop);
 462         } else {
 463           cached = 1;
 464         }
 465       } else if ((port0 = ip4_get_port(ip40, MAP_RECEIVER, p0->current_length)) < 0) {
 466         // Could not find port. We'll free the reassembly.
 467         error0 = MAP_ERROR_BAD_PROTOCOL;
 468         port0 = 0;
 469         map_ip4_reass_free(r, &fragments_to_drop);
 470       } else {
 471         r->port = port0;
 472         map_ip4_reass_get_fragments(r, &fragments_to_loopback);
 473       }
 474
 475 #ifdef MAP_IP4_REASS_COUNT_BYTES
 476       if (!cached && r) {
 477         r->forwarded += clib_host_to_net_u16(ip40->length) - 20;
 478         if (!ip4_get_fragment_more(ip40))
 479           r->expected_total = ip4_get_fragment_offset(ip40) * 8 + clib_host_to_net_u16(ip40->length) - 20;
 480         if(r->forwarded >= r->expected_total)
 481           map_ip4_reass_free(r, &fragments_to_drop);
 482       }
 483 #endif
 484
 485       map_ip4_reass_unlock();
 486
 487       // NOTE: Most operations have already been performed by ip4_map
 488       // All we need is the right destination address
 489       ip60->dst_address.as_u64[0] = map_get_pfx_net(d0, ip40->dst_address.as_u32, port0);
 490       ip60->dst_address.as_u64[1] = map_get_sfx_net(d0, ip40->dst_address.as_u32, port0);
 491
 492       if (PREDICT_FALSE(d0->mtu && (clib_net_to_host_u16(ip60->payload_length) + sizeof(*ip60) > d0->mtu))) {
 493         vnet_buffer(p0)->ip_frag.header_offset = sizeof(*ip60);
 494         vnet_buffer(p0)->ip_frag.next_index = IP4_FRAG_NEXT_IP6_LOOKUP;
 495         vnet_buffer(p0)->ip_frag.mtu = d0->mtu;
 496         vnet_buffer(p0)->ip_frag.flags = IP_FRAG_FLAG_IP6_HEADER;
 497         next0 = IP4_MAP_REASS_NEXT_IP4_FRAGMENT;
 498       }
 499
 500       if (PREDICT_FALSE(p0->flags & VLIB_BUFFER_IS_TRACED)) {
 501         map_ip4_map_reass_trace_t *tr = vlib_add_trace(vm, node, p0, sizeof(*tr));
 502         tr->map_domain_index = map_domain_index0;
 503         tr->port = port0;
 504         tr->cached = cached;
 505       }
 506
 507       if(cached) {
 508         //Dequeue the packet
 509         n_left_to_next++;
 510         to_next--;
 511       } else {
 512         if (error0 == MAP_ERROR_NONE)
 513           vlib_increment_combined_counter(cm + MAP_DOMAIN_COUNTER_TX, cpu_index, map_domain_index0, 1,
 514                                           clib_net_to_host_u16(ip60->payload_length) + 40);
 515         next0 = (error0 == MAP_ERROR_NONE) ? next0 : IP4_MAP_REASS_NEXT_DROP;
 516         p0->error = error_node->errors[error0];
 517         vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, pi0, next0);
 518       }
 519
 520       //Loopback when we reach the end of the inpu vector
 521       if(n_left_from == 0 && vec_len(fragments_to_loopback)) {
 522         from = vlib_frame_vector_args(frame);
 523         u32 len = vec_len(fragments_to_loopback);
 524         if(len <= VLIB_FRAME_SIZE) {
 525           memcpy(from, fragments_to_loopback, sizeof(u32)*len);
 526           n_left_from = len;
 527           vec_reset_length(fragments_to_loopback);
 528         } else {
 529           memcpy(from, fragments_to_loopback + (len - VLIB_FRAME_SIZE), sizeof(u32)*VLIB_FRAME_SIZE);
 530           n_left_from = VLIB_FRAME_SIZE;
 531           _vec_len(fragments_to_loopback) = len - VLIB_FRAME_SIZE;
 532         }
 533       }
 534     }
 535     vlib_put_next_frame(vm, node, next_index, n_left_to_next);
 536   }
 537
 538   map_send_all_to_node(vm, fragments_to_drop, node,
 539                        &error_node->errors[MAP_ERROR_FRAGMENT_DROPPED],
 540                        IP4_MAP_REASS_NEXT_DROP);
 541
 542   vec_free(fragments_to_drop);
 543   vec_free(fragments_to_loopback);
 544   return frame->n_vectors;
 545 }
 546
 547 static char *map_error_strings[] = {
 548 #define _(sym,string) string,
 549   foreach_map_error
 550 #undef _
 551 };
 552
 553 VLIB_REGISTER_NODE(ip4_map_node) = {
 554   .function = ip4_map,
 555   .name = "ip4-map",
 556   .vector_size = sizeof(u32),
 557   .format_trace = format_map_trace,
 558   .type = VLIB_NODE_TYPE_INTERNAL,
 559
 560   .n_errors = MAP_N_ERROR,
 561   .error_strings = map_error_strings,
 562
 563   .n_next_nodes = IP4_MAP_N_NEXT,
 564   .next_nodes = {
 565     [IP4_MAP_NEXT_IP6_LOOKUP] = "ip6-lookup",
 566 #ifdef MAP_SKIP_IP6_LOOKUP
 567     [IP4_MAP_NEXT_IP6_REWRITE] = "ip6-rewrite",
 568 #endif
 569     [IP4_MAP_NEXT_FRAGMENT] = "ip4-frag",
 570     [IP4_MAP_NEXT_REASS] = "ip4-map-reass",
 571     [IP4_MAP_NEXT_DROP] = "error-drop",
 572   },
 573 };
 574
 575 VLIB_REGISTER_NODE(ip4_map_reass_node) = {
 576   .function = ip4_map_reass,
 577   .name = "ip4-map-reass",
 578   .vector_size = sizeof(u32),
 579   .format_trace = format_ip4_map_reass_trace,
 580   .type = VLIB_NODE_TYPE_INTERNAL,
 581
 582   .n_errors = MAP_N_ERROR,
 583   .error_strings = map_error_strings,
 584
 585   .n_next_nodes = IP4_MAP_REASS_N_NEXT,
 586   .next_nodes = {
 587     [IP4_MAP_REASS_NEXT_IP6_LOOKUP] = "ip6-lookup",
 588     [IP4_MAP_REASS_NEXT_IP4_FRAGMENT] = "ip4-frag",
 589     [IP4_MAP_REASS_NEXT_DROP] = "error-drop",
 590   },
 591 };