FD.io VPP  v17.07.01-10-g3be13f0
Vector Packet Processing
ip6_to_ip4.h
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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 IPv6 to IPv4 translation
18  */
19 #ifndef __included_ip6_to_ip4_h__
20 #define __included_ip6_to_ip4_h__
21 
22 #include <vnet/ip/ip.h>
23 
24 /**
25  * IPv6 to IPv4 set call back function type
26  */
27 typedef int (*ip6_to_ip4_set_fn_t) (ip6_header_t * ip6, ip4_header_t * ip4,
28  void *ctx);
29 
30 /* *INDENT-OFF* */
32  { 0, 1, ~0, ~0,
33  2, 2, 9, 8,
34  12, 12, 12, 12,
35  12, 12, 12, 12,
36  12, 12, 12, 12,
37  12, 12, 12, 12,
38  24, 24, 24, 24,
39  24, 24, 24, 24,
40  24, 24, 24, 24,
41  24, 24, 24, 24
42  };
43 /* *INDENT-ON* */
44 
45 #define frag_id_6to4(id) ((id) ^ ((id) >> 16))
46 
47 /**
48  * @brief Parse some useful information from IPv6 header.
49  *
50  * @param ip6 IPv6 header.
51  * @param buff_len Buffer length.
52  * @param l4_protocol L4 protocol number.
53  * @param l4_offset L4 header offset.
54  * @param frag_hdr_offset Fragment header offset if present, 0 otherwise.
55  *
56  * @returns 0 on success, non-zero value otherwise.
57  */
59 ip6_parse (const ip6_header_t * ip6, u32 buff_len,
60  u8 * l4_protocol, u16 * l4_offset, u16 * frag_hdr_offset)
61 {
62  if (ip6->protocol == IP_PROTOCOL_IPV6_FRAGMENTATION)
63  {
64  *l4_protocol = ((ip6_frag_hdr_t *) (ip6 + 1))->next_hdr;
65  *frag_hdr_offset = sizeof (*ip6);
66  *l4_offset = sizeof (*ip6) + sizeof (ip6_frag_hdr_t);
67  }
68  else
69  {
70  *l4_protocol = ip6->protocol;
71  *frag_hdr_offset = 0;
72  *l4_offset = sizeof (*ip6);
73  }
74 
75  return (buff_len < (*l4_offset + 4)) ||
76  (clib_net_to_host_u16 (ip6->payload_length) <
77  (*l4_offset + 4 - sizeof (*ip6)));
78 }
79 
80 /**
81  * @brief Get TCP/UDP port number or ICMP id from IPv6 packet.
82  *
83  * @param ip6 IPv6 header.
84  * @param sender 1 get sender port, 0 get receiver port.
85  * @param buffer_len Buffer length.
86  *
87  * @returns Port number on success, 0 otherwise.
88  */
90 ip6_get_port (ip6_header_t * ip6, u8 sender, u16 buffer_len)
91 {
92  u8 l4_protocol;
93  u16 l4_offset;
94  u16 frag_offset;
95  u8 *l4;
96 
97  if (ip6_parse (ip6, buffer_len, &l4_protocol, &l4_offset, &frag_offset))
98  return 0;
99 
100  if (frag_offset &&
101  ip6_frag_hdr_offset (((ip6_frag_hdr_t *)
102  u8_ptr_add (ip6, frag_offset))))
103  return 0; //Can't deal with non-first fragment for now
104 
105  l4 = u8_ptr_add (ip6, l4_offset);
106  if (l4_protocol == IP_PROTOCOL_TCP || l4_protocol == IP_PROTOCOL_UDP)
107  {
108  return (sender) ? ((udp_header_t *) (l4))->src_port : ((udp_header_t
109  *)
110  (l4))->dst_port;
111  }
112  else if (l4_protocol == IP_PROTOCOL_ICMP6)
113  {
114  icmp46_header_t *icmp = (icmp46_header_t *) (l4);
115  if (icmp->type == ICMP6_echo_request)
116  {
117  return (sender) ? ((u16 *) (icmp))[2] : -1;
118  }
119  else if (icmp->type == ICMP6_echo_reply)
120  {
121  return (sender) ? -1 : ((u16 *) (icmp))[2];
122  }
123  }
124  return 0;
125 }
126 
127 /**
128  * @brief Convert type and code value from ICMP6 to ICMP4.
129  *
130  * @param icmp ICMP header.
131  * @param inner_ip6 Inner IPv6 header if present, 0 otherwise.
132  *
133  * @returns 0 on success, non-zero value otherwise.
134  */
136 icmp6_to_icmp_header (icmp46_header_t * icmp, ip6_header_t ** inner_ip6)
137 {
138  *inner_ip6 = NULL;
139  switch (icmp->type)
140  {
141  case ICMP6_echo_request:
142  icmp->type = ICMP4_echo_request;
143  break;
144  case ICMP6_echo_reply:
145  icmp->type = ICMP4_echo_reply;
146  break;
147  case ICMP6_destination_unreachable:
148  *inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8);
149 
150  switch (icmp->code)
151  {
152  case ICMP6_destination_unreachable_no_route_to_destination: //0
153  case ICMP6_destination_unreachable_beyond_scope_of_source_address: //2
154  case ICMP6_destination_unreachable_address_unreachable: //3
155  icmp->type = ICMP4_destination_unreachable;
156  icmp->code =
157  ICMP4_destination_unreachable_destination_unreachable_host;
158  break;
159  case ICMP6_destination_unreachable_destination_administratively_prohibited: //1
160  icmp->type =
161  ICMP4_destination_unreachable;
162  icmp->code =
163  ICMP4_destination_unreachable_communication_administratively_prohibited;
164  break;
165  case ICMP6_destination_unreachable_port_unreachable:
166  icmp->type = ICMP4_destination_unreachable;
167  icmp->code = ICMP4_destination_unreachable_port_unreachable;
168  break;
169  default:
170  return -1;
171  }
172  break;
173  case ICMP6_packet_too_big:
174  *inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8);
175 
176  icmp->type = ICMP4_destination_unreachable;
177  icmp->code = 4;
178  {
179  u32 advertised_mtu = clib_net_to_host_u32 (*((u32 *) (icmp + 1)));
180  advertised_mtu -= 20;
181  //FIXME: = minimum(advertised MTU-20, MTU_of_IPv4_nexthop, (MTU_of_IPv6_nexthop)-20)
182  ((u16 *) (icmp))[3] = clib_host_to_net_u16 (advertised_mtu);
183  }
184  break;
185 
186  case ICMP6_time_exceeded:
187  *inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8);
188 
189  icmp->type = ICMP4_time_exceeded;
190  break;
191 
192  case ICMP6_parameter_problem:
193  *inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8);
194 
195  switch (icmp->code)
196  {
197  case ICMP6_parameter_problem_erroneous_header_field:
198  icmp->type = ICMP4_parameter_problem;
199  icmp->code = ICMP4_parameter_problem_pointer_indicates_error;
200  u32 pointer = clib_net_to_host_u32 (*((u32 *) (icmp + 1)));
201  if (pointer >= 40)
202  return -1;
203 
204  ((u8 *) (icmp + 1))[0] =
206  break;
207  case ICMP6_parameter_problem_unrecognized_next_header:
208  icmp->type = ICMP4_destination_unreachable;
209  icmp->code = ICMP4_destination_unreachable_port_unreachable;
210  break;
211  case ICMP6_parameter_problem_unrecognized_option:
212  default:
213  return -1;
214  }
215  break;
216  default:
217  return -1;
218  break;
219  }
220  return 0;
221 }
222 
223 /**
224  * @brief Translate TOS value from IPv6 to IPv4.
225  *
226  * @param ip6 IPv6 header.
227  *
228  * @returns IPv4 TOS value.
229  */
232 {
233  return (clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label)
234  & 0x0ff00000) >> 20;
235 }
236 
237 /**
238  * @brief Translate ICMP6 packet to ICMP4.
239  *
240  * @param p Buffer to translate.
241  * @param fn The function to translate outer header.
242  * @param ctx A context passed in the outer header translate function.
243  * @param inner_fn The function to translate inner header.
244  * @param inner_ctx A context passed in the inner header translate function.
245  *
246  * @returns 0 on success, non-zero value otherwise.
247  */
248 always_inline int
250  ip6_to_ip4_set_fn_t inner_fn, void *inner_ctx)
251 {
252  ip6_header_t *ip6, *inner_ip6;
253  ip4_header_t *ip4, *inner_ip4;
254  u32 ip6_pay_len;
255  icmp46_header_t *icmp;
256  ip_csum_t csum;
257  int rv;
258 
259  ip6 = vlib_buffer_get_current (p);
260  ip6_pay_len = clib_net_to_host_u16 (ip6->payload_length);
261  icmp = (icmp46_header_t *) (ip6 + 1);
262  ASSERT (ip6_pay_len + sizeof (*ip6) <= p->current_length);
263 
264  //No extensions headers allowed here
265  if (ip6->protocol != IP_PROTOCOL_ICMP6)
266  return -1;
267 
268  //There are no fragmented ICMP messages, so no extension header for now
269  if (icmp6_to_icmp_header (icmp, &inner_ip6))
270  return -1;
271 
272  if (inner_ip6)
273  {
274  u16 *inner_L4_checksum, inner_l4_offset, inner_frag_offset,
275  inner_frag_id;
276  u8 *inner_l4, inner_protocol;
277 
278  //We have two headers to translate
279  // FROM
280  // [ IPv6 ]<- ext ->[IC][ IPv6 ]<- ext ->[L4 header ...
281  // Handled cases:
282  // [ IPv6 ][IC][ IPv6 ][L4 header ...
283  // [ IPv6 ][IC][ IPv6 ][Fr][L4 header ...
284  // TO
285  // [ IPv4][IC][ IPv4][L4 header ...
286 
287  if (ip6_parse (inner_ip6, ip6_pay_len - 8,
288  &inner_protocol, &inner_l4_offset, &inner_frag_offset))
289  return -1;
290 
291  inner_l4 = u8_ptr_add (inner_ip6, inner_l4_offset);
292  inner_ip4 =
293  (ip4_header_t *) u8_ptr_add (inner_l4, -sizeof (*inner_ip4));
294  if (inner_frag_offset)
295  {
296  ip6_frag_hdr_t *inner_frag =
297  (ip6_frag_hdr_t *) u8_ptr_add (inner_ip6, inner_frag_offset);
298  inner_frag_id = frag_id_6to4 (inner_frag->identification);
299  }
300  else
301  {
302  inner_frag_id = 0;
303  }
304 
305  //Do the translation of the inner packet
306  if (inner_protocol == IP_PROTOCOL_TCP)
307  {
308  inner_L4_checksum = (u16 *) u8_ptr_add (inner_l4, 16);
309  }
310  else if (inner_protocol == IP_PROTOCOL_UDP)
311  {
312  inner_L4_checksum = (u16 *) u8_ptr_add (inner_l4, 6);
313  }
314  else if (inner_protocol == IP_PROTOCOL_ICMP6)
315  {
316  icmp46_header_t *inner_icmp = (icmp46_header_t *) inner_l4;
317  //It cannot be of a different type as ip6_icmp_to_icmp6_in_place succeeded
318  inner_icmp->type = (inner_icmp->type == ICMP6_echo_request) ?
319  ICMP4_echo_request : ICMP4_echo_reply;
320  inner_protocol = IP_PROTOCOL_ICMP; //Will be copied to ip6 later
321  inner_L4_checksum = &inner_icmp->checksum;
322  }
323  else
324  {
325  return -1;
326  }
327 
328  csum = *inner_L4_checksum;
329  csum = ip_csum_sub_even (csum, inner_ip6->src_address.as_u64[0]);
330  csum = ip_csum_sub_even (csum, inner_ip6->src_address.as_u64[1]);
331  csum = ip_csum_sub_even (csum, inner_ip6->dst_address.as_u64[0]);
332  csum = ip_csum_sub_even (csum, inner_ip6->dst_address.as_u64[1]);
333  *inner_L4_checksum = ip_csum_fold (csum);
334 
335  if ((rv = inner_fn (inner_ip6, inner_ip4, inner_ctx)) != 0)
336  return rv;
337 
338  inner_ip4->ip_version_and_header_length =
340  inner_ip4->tos = ip6_translate_tos (inner_ip6);
341  inner_ip4->length =
342  u16_net_add (inner_ip6->payload_length,
343  sizeof (*ip4) + sizeof (*ip6) - inner_l4_offset);
344  inner_ip4->fragment_id = inner_frag_id;
345  inner_ip4->flags_and_fragment_offset =
346  clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS);
347  inner_ip4->ttl = inner_ip6->hop_limit;
348  inner_ip4->protocol = inner_protocol;
349  inner_ip4->checksum = ip4_header_checksum (inner_ip4);
350 
351  if (inner_ip4->protocol == IP_PROTOCOL_ICMP)
352  {
353  //Recompute ICMP checksum
354  icmp46_header_t *inner_icmp = (icmp46_header_t *) inner_l4;
355  inner_icmp->checksum = 0;
356  csum =
357  ip_incremental_checksum (0, inner_icmp,
358  clib_net_to_host_u16 (inner_ip4->length)
359  - sizeof (*inner_ip4));
360  inner_icmp->checksum = ~ip_csum_fold (csum);
361  }
362  else
363  {
364  //Update to new pseudo-header
365  csum = *inner_L4_checksum;
366  csum = ip_csum_add_even (csum, inner_ip4->src_address.as_u32);
367  csum = ip_csum_add_even (csum, inner_ip4->dst_address.as_u32);
368  *inner_L4_checksum = ip_csum_fold (csum);
369  }
370 
371  //Move up icmp header
372  ip4 = (ip4_header_t *) u8_ptr_add (inner_l4, -2 * sizeof (*ip4) - 8);
373  clib_memcpy (u8_ptr_add (inner_l4, -sizeof (*ip4) - 8), icmp, 8);
374  icmp = (icmp46_header_t *) u8_ptr_add (inner_l4, -sizeof (*ip4) - 8);
375  }
376  else
377  {
378  //Only one header to translate
379  ip4 = (ip4_header_t *) u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4));
380  }
381 
382  vlib_buffer_advance (p, (u32) (((u8 *) ip4) - ((u8 *) ip6)));
383 
384  if ((rv = fn (ip6, ip4, ctx)) != 0)
385  return rv;
386 
389  ip4->tos = ip6_translate_tos (ip6);
390  ip4->fragment_id = 0;
391  ip4->flags_and_fragment_offset = 0;
392  ip4->ttl = ip6->hop_limit;
393  ip4->protocol = IP_PROTOCOL_ICMP;
394  //TODO fix the length depending on offset length
395  ip4->length = u16_net_add (ip6->payload_length,
396  (inner_ip6 ==
397  NULL) ? sizeof (*ip4) : (2 * sizeof (*ip4) -
398  sizeof (*ip6)));
399  ip4->checksum = ip4_header_checksum (ip4);
400 
401  //Recompute ICMP checksum
402  icmp->checksum = 0;
403  csum =
404  ip_incremental_checksum (0, icmp,
405  clib_net_to_host_u16 (ip4->length) -
406  sizeof (*ip4));
407  icmp->checksum = ~ip_csum_fold (csum);
408 
409  return 0;
410 }
411 
412 /**
413  * @brief Translate IPv6 fragmented packet to IPv4.
414  *
415  * @param p Buffer to translate.
416  * @param fn The function to translate header.
417  * @param ctx A context passed in the header translate function.
418  *
419  * @returns 0 on success, non-zero value otherwise.
420  */
421 always_inline int
423 {
424  ip6_header_t *ip6;
425  ip6_frag_hdr_t *frag;
426  ip4_header_t *ip4;
427  u16 frag_id;
428  u8 frag_more;
429  u16 frag_offset;
430  u8 l4_protocol;
431  u16 l4_offset;
432  int rv;
433 
434  ip6 = vlib_buffer_get_current (p);
435 
436  if (ip6_parse
437  (ip6, p->current_length, &l4_protocol, &l4_offset, &frag_offset))
438  return -1;
439 
440  frag = (ip6_frag_hdr_t *) u8_ptr_add (ip6, frag_offset);
441  ip4 = (ip4_header_t *) u8_ptr_add (ip6, l4_offset - sizeof (*ip4));
442  vlib_buffer_advance (p, l4_offset - sizeof (*ip4));
443 
444  frag_id = frag_id_6to4 (frag->identification);
445  frag_more = ip6_frag_hdr_more (frag);
446  frag_offset = ip6_frag_hdr_offset (frag);
447 
448  if ((rv = fn (ip6, ip4, ctx)) != 0)
449  return rv;
450 
453  ip4->tos = ip6_translate_tos (ip6);
454  ip4->length = u16_net_add (ip6->payload_length,
455  sizeof (*ip4) - l4_offset + sizeof (*ip6));
456  ip4->fragment_id = frag_id;
458  clib_host_to_net_u16 (frag_offset |
459  (frag_more ? IP4_HEADER_FLAG_MORE_FRAGMENTS : 0));
460  ip4->ttl = ip6->hop_limit;
461  ip4->protocol =
462  (l4_protocol == IP_PROTOCOL_ICMP6) ? IP_PROTOCOL_ICMP : l4_protocol;
463  ip4->checksum = ip4_header_checksum (ip4);
464 
465  return 0;
466 }
467 
468 /**
469  * @brief Translate IPv6 UDP/TCP packet to IPv4.
470  *
471  * @param p Buffer to translate.
472  * @param fn The function to translate header.
473  * @param ctx A context passed in the header translate function.
474  *
475  * @returns 0 on success, non-zero value otherwise.
476  */
477 always_inline int
480 {
481  ip6_header_t *ip6;
482  u16 *checksum;
483  ip_csum_t csum = 0;
484  ip4_header_t *ip4;
485  u16 fragment_id;
486  u16 flags;
487  u16 frag_offset;
488  u8 l4_protocol;
489  u16 l4_offset;
490  int rv;
491 
492  ip6 = vlib_buffer_get_current (p);
493 
494  if (ip6_parse
495  (ip6, p->current_length, &l4_protocol, &l4_offset, &frag_offset))
496  return -1;
497 
498  if (l4_protocol == IP_PROTOCOL_TCP)
499  {
500  tcp_header_t *tcp = ip6_next_header (ip6);
501  checksum = &tcp->checksum;
502  }
503  else
504  {
505  udp_header_t *udp = ip6_next_header (ip6);
506  checksum = &udp->checksum;
507  //UDP checksum is optional over IPv4
508  if (!udp_checksum)
509  goto no_csum;
510  }
511 
512  csum = ip_csum_sub_even (*checksum, ip6->src_address.as_u64[0]);
513  csum = ip_csum_sub_even (csum, ip6->src_address.as_u64[1]);
514  csum = ip_csum_sub_even (csum, ip6->dst_address.as_u64[0]);
515  csum = ip_csum_sub_even (csum, ip6->dst_address.as_u64[1]);
516  *checksum = ip_csum_fold (csum);
517 
518 no_csum:
519  ip4 = (ip4_header_t *) u8_ptr_add (ip6, l4_offset - sizeof (*ip4));
520 
521  vlib_buffer_advance (p, l4_offset - sizeof (*ip4));
522 
523  if (PREDICT_FALSE (frag_offset))
524  {
525  //Only the first fragment
526  ip6_frag_hdr_t *hdr = (ip6_frag_hdr_t *) u8_ptr_add (ip6, frag_offset);
527  fragment_id = frag_id_6to4 (hdr->identification);
528  flags = clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS);
529  }
530  else
531  {
532  fragment_id = 0;
533  flags = 0;
534  }
535 
536  if ((rv = fn (ip6, ip4, ctx)) != 0)
537  return rv;
538 
541  ip4->tos = ip6_translate_tos (ip6);
542  ip4->length = u16_net_add (ip6->payload_length,
543  sizeof (*ip4) + sizeof (*ip6) - l4_offset);
544  ip4->fragment_id = fragment_id;
546  ip4->ttl = ip6->hop_limit;
547  ip4->protocol = l4_protocol;
548  ip4->checksum = ip4_header_checksum (ip4);
549 
550  //UDP checksum is optional over IPv4
551  if (!udp_checksum && l4_protocol == IP_PROTOCOL_UDP)
552  {
553  *checksum = 0;
554  }
555  else
556  {
557  csum = ip_csum_add_even (*checksum, ip4->dst_address.as_u32);
558  csum = ip_csum_add_even (csum, ip4->src_address.as_u32);
559  *checksum = ip_csum_fold (csum);
560  }
561 
562  return 0;
563 }
564 
565 #endif /* __included_ip6_to_ip4_h__ */
566 
567 /*
568  * fd.io coding-style-patch-verification: ON
569  *
570  * Local Variables:
571  * eval: (c-set-style "gnu")
572  * End:
573  */
static_always_inline u8 ip6_translate_tos(const ip6_header_t *ip6)
Translate TOS value from IPv6 to IPv4.
Definition: ip6_to_ip4.h:231
static u16 ip6_get_port(ip6_header_t *ip6, u8 sender, u16 buffer_len)
Get TCP/UDP port number or ICMP id from IPv6 packet.
Definition: ip6_to_ip4.h:90
u16 udp_checksum(udp_header_t *uh, u32 udp_len, void *ih, u8 version)
Definition: packets.c:114
ip4_address_t src_address
Definition: ip4_packet.h:164
static int icmp6_to_icmp(vlib_buffer_t *p, ip6_to_ip4_set_fn_t fn, void *ctx, ip6_to_ip4_set_fn_t inner_fn, void *inner_ctx)
Translate ICMP6 packet to ICMP4.
Definition: ip6_to_ip4.h:249
u64 as_u64[2]
Definition: ip6_packet.h:51
#define NULL
Definition: clib.h:55
uword ip_csum_t
Definition: ip_packet.h:90
u16 flags_and_fragment_offset
Definition: ip4_packet.h:145
struct _tcp_header tcp_header_t
#define u16_net_add(u, val)
Definition: map.h:514
ip6_address_t src_address
Definition: ip6_packet.h:341
static_always_inline int icmp6_to_icmp_header(icmp46_header_t *icmp, ip6_header_t **inner_ip6)
Convert type and code value from ICMP6 to ICMP4.
Definition: ip6_to_ip4.h:136
#define static_always_inline
Definition: clib.h:85
ip_csum_t ip_incremental_checksum(ip_csum_t sum, void *_data, uword n_bytes)
Definition: ip_checksum.c:43
#define always_inline
Definition: clib.h:84
ip4_address_t dst_address
Definition: ip4_packet.h:164
static_always_inline int ip6_parse(const ip6_header_t *ip6, u32 buff_len, u8 *l4_protocol, u16 *l4_offset, u16 *frag_hdr_offset)
Parse some useful information from IPv6 header.
Definition: ip6_to_ip4.h:59
#define frag_id_6to4(id)
Definition: ip6_to_ip4.h:45
static int ip6_to_ip4_tcp_udp(vlib_buffer_t *p, ip6_to_ip4_set_fn_t fn, void *ctx, u8 udp_checksum)
Translate IPv6 UDP/TCP packet to IPv4.
Definition: ip6_to_ip4.h:478
#define ip6_frag_hdr_more(hdr)
Definition: ip6_packet.h:522
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:71
static void * vlib_buffer_get_current(vlib_buffer_t *b)
Get pointer to current data to process.
Definition: buffer.h:188
#define PREDICT_FALSE(x)
Definition: clib.h:97
#define IP4_HEADER_FLAG_MORE_FRAGMENTS
Definition: ip4_packet.h:146
#define clib_memcpy(a, b, c)
Definition: string.h:69
static void * ip6_next_header(ip6_header_t *i)
Definition: ip6_packet.h:351
#define ip6_frag_hdr_offset(hdr)
Definition: ip6_packet.h:519
#define ASSERT(truth)
#define u8_ptr_add(ptr, index)
Definition: map.h:513
unsigned int u32
Definition: types.h:88
static ip_csum_t ip_csum_sub_even(ip_csum_t c, ip_csum_t x)
Definition: ip_packet.h:117
static u8 icmp6_to_icmp_updater_pointer_table[]
Definition: ip6_to_ip4.h:31
static void vlib_buffer_advance(vlib_buffer_t *b, word l)
Advance current data pointer by the supplied (signed!) amount.
Definition: buffer.h:201
u32 ip_version_traffic_class_and_flow_label
Definition: ip6_packet.h:328
unsigned short u16
Definition: types.h:57
u16 payload_length
Definition: ip6_packet.h:332
unsigned char u8
Definition: types.h:56
#define IP4_VERSION_AND_HEADER_LENGTH_NO_OPTIONS
Definition: ip4_packet.h:188
u8 ip_version_and_header_length
Definition: ip4_packet.h:132
u32 flags
Definition: vhost-user.h:76
int(* ip6_to_ip4_set_fn_t)(ip6_header_t *ip6, ip4_header_t *ip4, void *ctx)
IPv6 to IPv4 set call back function type.
Definition: ip6_to_ip4.h:27
static u16 ip4_header_checksum(ip4_header_t *i)
Definition: ip4_packet.h:239
static u16 ip_csum_fold(ip_csum_t c)
Definition: ip_packet.h:145
static ip_csum_t ip_csum_add_even(ip_csum_t c, ip_csum_t x)
Definition: ip_packet.h:101
ip6_address_t dst_address
Definition: ip6_packet.h:341
static int ip6_to_ip4_fragmented(vlib_buffer_t *p, ip6_to_ip4_set_fn_t fn, void *ctx)
Translate IPv6 fragmented packet to IPv4.
Definition: ip6_to_ip4.h:422