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path: root/src/plugins/ioam/encap/ip6_ioam_trace.h
AgeCommit message (Expand)AuthorFilesLines
2017-03-07In-band OAM active probe (VPP-471)AkshayaNadahalli1-0/+12
2017-03-06ioam: manycast using iOAM and SR (VPP-628)Shwetha Bhandari1-1/+2
2017-02-13VPP-632 : InBand OAM AnalyserAkshayaNadahalli1-0/+38
103' href='#n103'>103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * ip6/packet.h: ip6 packet format
 *
 * Copyright (c) 2008 Eliot Dresselhaus
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef included_ip6_packet_h
#define included_ip6_packet_h

#include <vnet/tcp/tcp_packet.h>
#include <vnet/ip/ip4_packet.h>

typedef union
{
  u8 as_u8[16];
  u16 as_u16[8];
  u32 as_u32[4];
  u64 as_u64[2];
  u64x2 as_u128;
  uword as_uword[16 / sizeof (uword)];
}
__clib_packed ip6_address_t;

STATIC_ASSERT_SIZEOF (ip6_address_t, 16);

typedef struct
{
  ip6_address_t addr, mask;
} ip6_address_and_mask_t;

/* Packed so that the mhash key doesn't include uninitialized pad bytes */
/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  /* IP address must be first for ip_interface_address_get_address() to work */
  ip6_address_t ip6_addr;
  u32 fib_index;
}) ip6_address_fib_t;
/* *INDENT-ON* */

always_inline void
ip6_addr_fib_init (ip6_address_fib_t * addr_fib,
		   const ip6_address_t * address, u32 fib_index)
{
  addr_fib->ip6_addr = *address;
  addr_fib->fib_index = fib_index;
}

/* Special addresses:
   unspecified		::/128
   loopback		::1/128
   global unicast       2000::/3
   unique local unicast fc00::/7
   link local unicast	fe80::/10
   multicast		ff00::/8
   ietf reserved	everything else. */

#define foreach_ip6_multicast_address_scope	\
  _ (loopback, 0x1)				\
  _ (link_local, 0x2)				\
  _ (admin_local, 0x4)				\
  _ (site_local, 0x5)				\
  _ (organization_local, 0x8)			\
  _ (global, 0xe)

#define foreach_ip6_multicast_link_local_group_id	\
  _ (all_hosts, 0x1)					\
  _ (all_routers, 0x2)					\
  _ (rip_routers, 0x9)					\
  _ (eigrp_routers, 0xa)				\
  _ (pim_routers, 0xd)                            \
 _ (mldv2_routers, 0x16)

typedef enum
{
#define _(f,n) IP6_MULTICAST_SCOPE_##f = n,
  foreach_ip6_multicast_address_scope
#undef _
} ip6_multicast_address_scope_t;

typedef enum
{
#define _(f,n) IP6_MULTICAST_GROUP_ID_##f = n,
  foreach_ip6_multicast_link_local_group_id
#undef _
} ip6_multicast_link_local_group_id_t;

always_inline uword
ip6_address_is_multicast (const ip6_address_t * a)
{
  return a->as_u8[0] == 0xff;
}

always_inline void
ip6_address_copy (ip6_address_t * dst, const ip6_address_t * src)
{
  dst->as_u64[0] = src->as_u64[0];
  dst->as_u64[1] = src->as_u64[1];
}

always_inline void
ip6_set_reserved_multicast_address (ip6_address_t * a,
				    ip6_multicast_address_scope_t scope,
				    u16 id)
{
  a->as_u64[0] = a->as_u64[1] = 0;
  a->as_u16[0] = clib_host_to_net_u16 (0xff00 | scope);
  a->as_u16[7] = clib_host_to_net_u16 (id);
}

always_inline void
ip6_set_solicited_node_multicast_address (ip6_address_t * a, u32 id)
{
  /* 0xff02::1:ffXX:XXXX. */
  a->as_u64[0] = a->as_u64[1] = 0;
  a->as_u16[0] = clib_host_to_net_u16 (0xff02);
  a->as_u8[11] = 1;
  ASSERT ((id >> 24) == 0);
  id |= 0xff << 24;
  a->as_u32[3] = clib_host_to_net_u32 (id);
}

always_inline void
ip6_multicast_ethernet_address (u8 * ethernet_address, u32 group_id)
{
  ethernet_address[0] = 0x33;
  ethernet_address[1] = 0x33;
  ethernet_address[2] = ((group_id >> 24) & 0xff);
  ethernet_address[3] = ((group_id >> 16) & 0xff);
  ethernet_address[4] = ((group_id >> 8) & 0xff);
  ethernet_address[5] = ((group_id >> 0) & 0xff);
}

always_inline uword
ip6_address_is_equal (const ip6_address_t * a, const ip6_address_t * b)
{
  int i;
  for (i = 0; i < ARRAY_LEN (a->as_uword); i++)
    if (a->as_uword[i] != b->as_uword[i])
      return 0;
  return 1;
}

always_inline uword
ip6_address_is_equal_masked (const ip6_address_t * a,
			     const ip6_address_t * b,
			     const ip6_address_t * mask)
{
  int i;
  for (i = 0; i < ARRAY_LEN (a->as_uword); i++)
    {
      uword a_masked, b_masked;
      a_masked = a->as_uword[i] & mask->as_uword[i];
      b_masked = b->as_uword[i] & mask->as_uword[i];

      if (a_masked != b_masked)
	return 0;
    }
  return 1;
}

always_inline void
ip6_address_mask (ip6_address_t * a, const ip6_address_t * mask)
{
  int i;
  for (i = 0; i < ARRAY_LEN (a->as_uword); i++)
    a->as_uword[i] &= mask->as_uword[i];
}

always_inline void
ip6_address_set_zero (ip6_address_t * a)
{
  int i;
  for (i = 0; i < ARRAY_LEN (a->as_uword); i++)
    a->as_uword[i] = 0;
}

always_inline void
ip6_address_mask_from_width (ip6_address_t * a, u32 width)
{
  int i, byte, bit, bitnum;
  ASSERT (width <= 128);
  clib_memset (a, 0, sizeof (a[0]));
  for (i = 0; i < width; i++)
    {
      bitnum = (7 - (i & 7));
      byte = i / 8;
      bit = 1 << bitnum;
      a->as_u8[byte] |= bit;
    }
}

always_inline uword
ip6_address_is_zero (const ip6_address_t * a)
{
  int i;
  for (i = 0; i < ARRAY_LEN (a->as_uword); i++)
    if (a->as_uword[i] != 0)
      return 0;
  return 1;
}

/* Check for unspecified address ::0 */
always_inline uword
ip6_address_is_unspecified (const ip6_address_t * a)
{
  return ip6_address_is_zero (a);
}

/* Check for loopback address ::1 */
always_inline uword
ip6_address_is_loopback (const ip6_address_t * a)
{
  return (a->as_u64[0] == 0 &&
	  a->as_u32[2] == 0 &&
	  a->as_u16[6] == 0 && a->as_u8[14] == 0 && a->as_u8[15] == 1);
}

/* Check for link local unicast fe80::/10. */
always_inline uword
ip6_address_is_link_local_unicast (const ip6_address_t * a)
{
  return a->as_u8[0] == 0xfe && (a->as_u8[1] & 0xc0) == 0x80;
}

/* Check for unique local unicast fc00::/7. */
always_inline uword
ip6_address_is_local_unicast (const ip6_address_t * a)
{
  return (a->as_u8[0] & 0xfe) == 0xfc;
}

/* Check for unique global unicast 2000::/3. */
always_inline uword
ip6_address_is_global_unicast (const ip6_address_t * a)
{
  return (a->as_u8[0] & 0xe0) == 0x20;
}

/* Check for solicited node multicast 0xff02::1:ff00:0/104 */
always_inline uword
ip6_is_solicited_node_multicast_address (const ip6_address_t * a)
{
  return (a->as_u32[0] == clib_host_to_net_u32 (0xff020000)
	  && a->as_u32[1] == 0
	  && a->as_u32[2] == clib_host_to_net_u32 (1)
	  && a->as_u8[12] == 0xff);
}

always_inline u32
ip6_address_hash_to_u32 (const ip6_address_t * a)
{
  return (a->as_u32[0] ^ a->as_u32[1] ^ a->as_u32[2] ^ a->as_u32[3]);
}

always_inline u64
ip6_address_hash_to_u64 (const ip6_address_t * a)
{
  return (a->as_u64[0] ^ a->as_u64[1]);
}

typedef struct
{
  /* 4 bit version, 8 bit traffic class and 20 bit flow label. */
  u32 ip_version_traffic_class_and_flow_label;

  /* Total packet length not including this header (but including
     any extension headers if present). */
  u16 payload_length;

  /* Protocol for next header. */
  u8 protocol;

  /* Hop limit decremented by router at each hop. */
  u8 hop_limit;

  /* Source and destination address. */
  ip6_address_t src_address, dst_address;
} ip6_header_t;

#define IP6_PACKET_TC_MASK 0x0FF00000
#define IP6_PACKET_DSCP_MASK 0x0FC00000
#define IP6_PACKET_ECN_MASK 0x00300000
#define IP6_PACKET_FL_MASK   0x000FFFFF

always_inline ip_dscp_t
ip6_traffic_class (const ip6_header_t * i)
{
  return (i->ip_version_traffic_class_and_flow_label & IP6_PACKET_TC_MASK) >>
    20;
}

static_always_inline ip_dscp_t
ip6_traffic_class_network_order (const ip6_header_t * ip6)
{
  return (clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label)
	  & IP6_PACKET_TC_MASK) >> 20;
}

static_always_inline ip_dscp_t
ip6_dscp_network_order (const ip6_header_t * ip6)
{
  return (clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label)
	  & IP6_PACKET_DSCP_MASK) >> 22;
}

static_always_inline ip_ecn_t
ip6_ecn_network_order (const ip6_header_t * ip6)
{
  return (clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label)
	  & IP6_PACKET_ECN_MASK) >> 20;
}

static_always_inline void
ip6_set_traffic_class_network_order (ip6_header_t * ip6, ip_dscp_t dscp)
{
  u32 tmp =
    clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label);
  tmp &= 0xf00fffff;
  tmp |= (dscp << 20);
  ip6->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 (tmp);
}

static_always_inline void
ip6_set_dscp_network_order (ip6_header_t * ip6, ip_dscp_t dscp)
{
  u32 tmp =
    clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label);
  tmp &= 0xf03fffff;
  tmp |= (dscp << 22);
  ip6->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 (tmp);
}

static_always_inline void
ip6_set_ecn_network_order (ip6_header_t * ip6, ip_ecn_t ecn)
{
  u32 tmp =
    clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label);
  tmp &= 0xffcfffff;
  tmp |= ((0x3 & ecn) << 20);
  ip6->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 (tmp);
}

static_always_inline u32
ip6_flow_label_network_order (const ip6_header_t *ip6)
{
  u32 tmp =
    clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label);
  return (tmp & 0xfffff);
}

static_always_inline void
ip6_set_flow_label_network_order (ip6_header_t *ip6, u32 flow_label)
{
  u32 tmp =
    clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label);
  tmp &= 0xfff00000;
  tmp |= flow_label & 0x000fffff;
  ip6->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 (tmp);
}

static_always_inline u32
ip6_hop_limit_network_order (const ip6_header_t *ip6)
{
  return (ip6->hop_limit);
}

static_always_inline void
ip6_set_hop_limit_network_order (ip6_header_t *ip6, u8 hop_limit)
{
  ip6->hop_limit = hop_limit;
}

always_inline void *
ip6_next_header (ip6_header_t * i)
{
  return (void *) (i + 1);
}

always_inline void
ip6_copy_header (ip6_header_t * dst, const ip6_header_t * src)
{
  dst->ip_version_traffic_class_and_flow_label =
    src->ip_version_traffic_class_and_flow_label;
  dst->payload_length = src->payload_length;
  dst->protocol = src->protocol;
  dst->hop_limit = src->hop_limit;

  dst->src_address.as_uword[0] = src->src_address.as_uword[0];
  dst->src_address.as_uword[1] = src->src_address.as_uword[1];
  dst->dst_address.as_uword[0] = src->dst_address.as_uword[0];
  dst->dst_address.as_uword[1] = src->dst_address.as_uword[1];
}

always_inline void
ip6_tcp_reply_x1 (ip6_header_t * ip0, tcp_header_t * tcp0)
{
  {
    ip6_address_t src0, dst0;

    src0 = ip0->src_address;
    dst0 = ip0->dst_address;
    ip0->src_address = dst0;
    ip0->dst_address = src0;
  }

  {
    u16 src0, dst0;

    src0 = tcp0->src;
    dst0 = tcp0->dst;
    tcp0->src = dst0;
    tcp0->dst = src0;
  }
}

always_inline void
ip6_tcp_reply_x2 (ip6_header_t * ip0, ip6_header_t * ip1,
		  tcp_header_t * tcp0, tcp_header_t * tcp1)
{
  {
    ip6_address_t src0, dst0, src1, dst1;

    src0 = ip0->src_address;
    src1 = ip1->src_address;
    dst0 = ip0->dst_address;
    dst1 = ip1->dst_address;
    ip0->src_address = dst0;
    ip1->src_address = dst1;
    ip0->dst_address = src0;
    ip1->dst_address = src1;
  }

  {
    u16 src0, dst0, src1, dst1;

    src0 = tcp0->src;
    src1 = tcp1->src;
    dst0 = tcp0->dst;
    dst1 = tcp1->dst;
    tcp0->src = dst0;
    tcp1->src = dst1;
    tcp0->dst = src0;
    tcp1->dst = src1;
  }
}


/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  u8 data;
}) ip6_pad1_option_t;
/* *INDENT-ON* */

/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  u8 type;
  u8 len;
  u8 data[0];
}) ip6_padN_option_t;
/* *INDENT-ON* */

/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
#define IP6_MLDP_ALERT_TYPE  0x5
  u8 type;
  u8 len;
  u16 value;
}) ip6_router_alert_option_t;
/* *INDENT-ON* */

/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  u8 next_hdr;
  /* Length of this header plus option data in 8 byte units. */
  u8 n_data_u64s;
}) ip6_ext_header_t;
/* *INDENT-ON* */

#define foreach_ext_hdr_type \
  _(IP6_HOP_BY_HOP_OPTIONS) \
  _(IPV6_ROUTE) \
  _(IPV6_FRAGMENTATION) \
  _(IPSEC_ESP) \
  _(IPSEC_AH) \
  _(IP6_DESTINATION_OPTIONS) \
  _(MOBILITY) \
  _(HIP) \
  _(SHIM6)

always_inline u8
ip6_ext_hdr (u8 nexthdr)
{
#ifdef CLIB_HAVE_VEC128
  static const u8x16 ext_hdr_types = {
#define _(x) IP_PROTOCOL_##x,
    foreach_ext_hdr_type
#undef _
  };

  return !u8x16_is_all_zero (ext_hdr_types == u8x16_splat (nexthdr));
#else
  /*
   * find out if nexthdr is an extension header or a protocol
   */
  return 0
#define _(x) || (nexthdr == IP_PROTOCOL_##x)
    foreach_ext_hdr_type;
#undef _
#endif
}

#define ip6_ext_header_len(p)  ((((ip6_ext_header_t *)(p))->n_data_u64s+1) << 3)
#define ip6_ext_authhdr_len(p) ((((ip6_ext_header_t *)(p))->n_data_u64s+2) << 2)

always_inline void *
ip6_ext_next_header (ip6_ext_header_t * ext_hdr)
{
  return (void *) ((u8 *) ext_hdr + ip6_ext_header_len (ext_hdr));
}

always_inline int
vlib_object_within_buffer_data (vlib_main_t * vm, vlib_buffer_t * b,
				void *obj, size_t len)
{
  u8 *o = obj;
  if (o < b->data ||
      o + len > b->data + vlib_buffer_get_default_data_size (vm))
    return 0;
  return 1;
}

/*
 * find ipv6 extension header within ipv6 header within buffer b
 *
 * @param vm
 * @param b buffer to limit search to
 * @param ip6_header ipv6 header
 * @param header_type extension header type to search for
 * @param[out] prev_ext_header address of header preceding found header
 */
always_inline void *
ip6_ext_header_find (vlib_main_t * vm, vlib_buffer_t * b,
		     ip6_header_t * ip6_header, u8 header_type,
		     ip6_ext_header_t ** prev_ext_header)
{
  ip6_ext_header_t *prev = NULL;
  ip6_ext_header_t *result = NULL;
  if ((ip6_header)->protocol == header_type)
    {
      result = (void *) (ip6_header + 1);
      if (!vlib_object_within_buffer_data (vm, b, result,
					   ip6_ext_header_len (result)))
	{
	  result = NULL;
	}
    }
  else
    {
      result = NULL;
      prev = (void *) (ip6_header + 1);
      while (ip6_ext_hdr (prev->next_hdr) && prev->next_hdr != header_type)
	{
	  prev = ip6_ext_next_header (prev);
	  if (!vlib_object_within_buffer_data (vm, b, prev,
					       ip6_ext_header_len (prev)))
	    {
	      prev = NULL;
	      break;
	    }
	}
      if (prev && (prev->next_hdr == header_type))
	{
	  result = ip6_ext_next_header (prev);
	  if (!vlib_object_within_buffer_data (vm, b, result,
					       ip6_ext_header_len (result)))
	    {
	      result = NULL;
	    }
	}
    }
  if (prev_ext_header)
    {
      *prev_ext_header = prev;
    }
  return result;
}

/*
 * walk extension headers, looking for a specific extension header and last
 * extension header, calculating length of all extension headers
 *
 * @param vm
 * @param b buffer to limit search to
 * @param ip6_header ipv6 header
 * @param find_hdr extension header to look for (ignored if ext_hdr is NULL)
 * @param length[out] length of all extension headers
 * @param ext_hdr[out] extension header of type find_hdr (may be NULL)
 * @param last_ext_hdr[out] last extension header (may be NULL)
 *
 * @return 0 on success, -1 on failure (ext headers crossing buffer boundary)
 */
always_inline int
ip6_walk_ext_hdr (vlib_main_t * vm, vlib_buffer_t * b,
		  const ip6_header_t * ip6_header, u8 find_hdr, u32 * length,
		  ip6_ext_header_t ** ext_hdr,
		  ip6_ext_header_t ** last_ext_hdr)
{
  if (!ip6_ext_hdr (ip6_header->protocol))
    {
      *length = 0;
      *ext_hdr = NULL;
      *last_ext_hdr = NULL;
      return 0;
    }
  *length = 0;
  ip6_ext_header_t *h = (void *) (ip6_header + 1);
  if (!vlib_object_within_buffer_data (vm, b, h, ip6_ext_header_len (h)))
    {
      return -1;
    }
  *length += ip6_ext_header_len (h);
  *last_ext_hdr = h;
  *ext_hdr = NULL;
  if (ip6_header->protocol == find_hdr)
    {
      *ext_hdr = h;
    }
  while (ip6_ext_hdr (h->next_hdr))
    {
      if (h->next_hdr == find_hdr)
	{
	  h = ip6_ext_next_header (h);
	  *ext_hdr = h;
	}
      else
	{
	  h = ip6_ext_next_header (h);
	}
      if (!vlib_object_within_buffer_data (vm, b, h, ip6_ext_header_len (h)))
	{
	  return -1;
	}
      *length += ip6_ext_header_len (h);
      *last_ext_hdr = h;
    }
  return 0;
}

/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  u8 next_hdr;
  /* Length of this header plus option data in 8 byte units. */
  u8 n_data_u64s;
  u8 data[0];
}) ip6_hop_by_hop_ext_t;
/* *INDENT-ON* */

/* *INDENT-OFF* */
typedef CLIB_PACKED (struct {
  u8 next_hdr;
  u8 rsv;
  u16 fragment_offset_and_more;
  u32 identification;
}) ip6_frag_hdr_t;
/* *INDENT-ON* */

#define ip6_frag_hdr_offset(hdr) \
  (clib_net_to_host_u16((hdr)->fragment_offset_and_more) >> 3)

#define ip6_frag_hdr_offset_bytes(hdr) \
  (8 * ip6_frag_hdr_offset(hdr))

#define ip6_frag_hdr_more(hdr) \
  (clib_net_to_host_u16((hdr)->fragment_offset_and_more) & 0x1)

#define ip6_frag_hdr_offset_and_more(offset, more) \
  clib_host_to_net_u16(((offset) << 3) + !!(more))

#endif /* included_ip6_packet_h */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */