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authorChris Luke <chrisy@flirble.org>2016-05-14 12:06:42 -0400
committerDave Barach <openvpp@barachs.net>2016-05-16 11:48:16 +0000
commitaa761e128158e788f4046e24039e9ae0ee425dbb (patch)
treeeee05717b93c24c596413d8e48a52db3c95f33c0 /vlib/example
parent9c5b2b301c1a2cc39b76c4a9570ce18a5eaa37be (diff)
VPP-57 Add missing license headers in doc files
Change-Id: Icd1f8952f66d3cee027c59f3148c67f1839de306 Signed-off-by: Chris Luke <chrisy@flirble.org>
Diffstat (limited to 'vlib/example')
-rw-r--r--vlib/example/dir.dox16
1 files changed, 16 insertions, 0 deletions
diff --git a/vlib/example/dir.dox b/vlib/example/dir.dox
index 8dc0fee7749..d3ac0ee431b 100644
--- a/vlib/example/dir.dox
+++ b/vlib/example/dir.dox
@@ -1,3 +1,19 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Copyright (c) 2016 Comcast Cable Communications Management, LLC.
+ *
+ * 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.
+ */
/* Doxygen directory documentation */
/**
@dir
ref='#n187'>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 
/*
 * Copyright (c) 2017 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.
 */
/**
 * @file
 * @brief IPv4 to IPv6 translation
 */
#ifndef __included_ip4_to_ip6_h__
#define __included_ip4_to_ip6_h__

#include <vnet/ip/ip.h>


/**
 * IPv4 to IPv6 set call back function type
 */
typedef int (*ip4_to_ip6_set_fn_t) (vlib_buffer_t * b, ip4_header_t * ip4,
				    ip6_header_t * ip6, void *ctx);

/* *INDENT-OFF* */
static u8 icmp_to_icmp6_updater_pointer_table[] =
  { 0, 1, 4, 4, ~0,
    ~0, ~0, ~0, 7, 6,
    ~0, ~0, 8, 8, 8,
    8, 24, 24, 24, 24
  };
/* *INDENT-ON* */

#define frag_id_4to6(id) (id)

/**
 * @brief Get TCP/UDP port number or ICMP id from IPv4 packet.
 *
 * @param ip4        IPv4 header.
 * @param sender     1 get sender port, 0 get receiver port.
 *
 * @returns Port number on success, 0 otherwise.
 */
always_inline u16
ip4_get_port (ip4_header_t * ip, u8 sender)
{
  if (ip->ip_version_and_header_length != 0x45 ||
      ip4_get_fragment_offset (ip))
    return 0;

  if (PREDICT_TRUE ((ip->protocol == IP_PROTOCOL_TCP) ||
		    (ip->protocol == IP_PROTOCOL_UDP)))
    {
      udp_header_t *udp = (void *) (ip + 1);
      return (sender) ? udp->src_port : udp->dst_port;
    }
  else if (ip->protocol == IP_PROTOCOL_ICMP)
    {
      icmp46_header_t *icmp = (void *) (ip + 1);
      if (icmp->type == ICMP4_echo_request || icmp->type == ICMP4_echo_reply)
	{
	  return *((u16 *) (icmp + 1));
	}
      else if (clib_net_to_host_u16 (ip->length) >= 64)
	{
	  ip = (ip4_header_t *) (icmp + 2);
	  if (PREDICT_TRUE ((ip->protocol == IP_PROTOCOL_TCP) ||
			    (ip->protocol == IP_PROTOCOL_UDP)))
	    {
	      udp_header_t *udp = (void *) (ip + 1);
	      return (sender) ? udp->dst_port : udp->src_port;
	    }
	  else if (ip->protocol == IP_PROTOCOL_ICMP)
	    {
	      icmp46_header_t *icmp = (void *) (ip + 1);
	      if (icmp->type == ICMP4_echo_request ||
		  icmp->type == ICMP4_echo_reply)
		{
		  return *((u16 *) (icmp + 1));
		}
	    }
	}
    }
  return 0;
}

/**
 * @brief Convert type and code value from ICMP4 to ICMP6.
 *
 * @param icmp      ICMP header.
 * @param inner_ip4 Inner IPv4 header if present, 0 otherwise.
 *
 * @returns 0 on success, non-zero value otherwise.
 */
always_inline int
icmp_to_icmp6_header (icmp46_header_t * icmp, ip4_header_t ** inner_ip4)
{
  *inner_ip4 = NULL;
  switch (icmp->type)
    {
    case ICMP4_echo_reply:
      icmp->type = ICMP6_echo_reply;
      break;
    case ICMP4_echo_request:
      icmp->type = ICMP6_echo_request;
      break;
    case ICMP4_destination_unreachable:
      *inner_ip4 = (ip4_header_t *) (((u8 *) icmp) + 8);

      switch (icmp->code)
	{
	case ICMP4_destination_unreachable_destination_unreachable_net:	//0
	case ICMP4_destination_unreachable_destination_unreachable_host:	//1
	  icmp->type = ICMP6_destination_unreachable;
	  icmp->code = ICMP6_destination_unreachable_no_route_to_destination;
	  break;
	case ICMP4_destination_unreachable_protocol_unreachable:	//2
	  icmp->type = ICMP6_parameter_problem;
	  icmp->code = ICMP6_parameter_problem_unrecognized_next_header;
	  break;
	case ICMP4_destination_unreachable_port_unreachable:	//3
	  icmp->type = ICMP6_destination_unreachable;
	  icmp->code = ICMP6_destination_unreachable_port_unreachable;
	  break;
	case ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set:	//4
	  icmp->type =
	    ICMP6_packet_too_big;
	  icmp->code = 0;
	  {
	    u32 advertised_mtu = clib_net_to_host_u32 (*((u32 *) (icmp + 1)));
	    if (advertised_mtu)
	      advertised_mtu += 20;
	    else
	      advertised_mtu = 1000;	//FIXME ! (RFC 1191 - plateau value)

	    //FIXME: = minimum(advertised MTU+20, MTU_of_IPv6_nexthop, (MTU_of_IPv4_nexthop)+20)
	    *((u32 *) (icmp + 1)) = clib_host_to_net_u32 (advertised_mtu);
	  }
	  break;

	case ICMP4_destination_unreachable_source_route_failed:	//5
	case ICMP4_destination_unreachable_destination_network_unknown:	//6
	case ICMP4_destination_unreachable_destination_host_unknown:	//7
	case ICMP4_destination_unreachable_source_host_isolated:	//8
	case ICMP4_destination_unreachable_network_unreachable_for_type_of_service:	//11
	case ICMP4_destination_unreachable_host_unreachable_for_type_of_service:	//12
	  icmp->type =
	    ICMP6_destination_unreachable;
	  icmp->code = ICMP6_destination_unreachable_no_route_to_destination;
	  break;
	case ICMP4_destination_unreachable_network_administratively_prohibited:	//9
	case ICMP4_destination_unreachable_host_administratively_prohibited:	//10
	case ICMP4_destination_unreachable_communication_administratively_prohibited:	//13
	case ICMP4_destination_unreachable_precedence_cutoff_in_effect:	//15
	  icmp->type = ICMP6_destination_unreachable;
	  icmp->code =
	    ICMP6_destination_unreachable_destination_administratively_prohibited;
	  break;
	case ICMP4_destination_unreachable_host_precedence_violation:	//14
	default:
	  return -1;
	}
      break;

    case ICMP4_time_exceeded:	//11
      *inner_ip4 = (ip4_header_t *) (((u8 *) icmp) + 8);
      icmp->type = ICMP6_time_exceeded;
      break;

    case ICMP4_parameter_problem:
      *inner_ip4 = (ip4_header_t *) (((u8 *) icmp) + 8);

      switch (icmp->code)
	{
	case ICMP4_parameter_problem_pointer_indicates_error:
	case ICMP4_parameter_problem_bad_length:
	  icmp->type = ICMP6_parameter_problem;
	  icmp->code = ICMP6_parameter_problem_erroneous_header_field;
	  {
	    u8 ptr =
	      icmp_to_icmp6_updater_pointer_table[*((u8 *) (icmp + 1))];
	    if (ptr == 0xff)
	      return -1;

	    *((u32 *) (icmp + 1)) = clib_host_to_net_u32 (ptr);
	  }
	  break;
	default:
	  //All other codes cause error
	  return -1;
	}
      break;

    default:
      //All other types cause error
      return -1;
      break;
    }
  return 0;
}

/**
 * @brief Translate ICMP4 packet to ICMP6.
 *
 * @param p         Buffer to translate.
 * @param fn        The function to translate outer header.
 * @param ctx       A context passed in the outer header translate function.
 * @param inner_fn  The function to translate inner header.
 * @param inner_ctx A context passed in the inner header translate function.
 *
 * @returns 0 on success, non-zero value otherwise.
 */
always_inline int
icmp_to_icmp6 (vlib_buffer_t * p, ip4_to_ip6_set_fn_t fn, void *ctx,
	       ip4_to_ip6_set_fn_t inner_fn, void *inner_ctx)
{
  ip4_header_t *ip4, *inner_ip4;
  ip6_header_t *ip6, *inner_ip6;
  u32 ip_len;
  icmp46_header_t *icmp;
  ip_csum_t csum;
  ip6_frag_hdr_t *inner_frag;
  ip6_frag_hdr_t *outer_frag= NULL;
  u32 inner_frag_id;
  u32 inner_frag_offset;
  u32 outer_frag_id;
  u8 inner_frag_more;
  u16 *inner_L4_checksum = 0;
  int rv;

  ip4 = vlib_buffer_get_current (p);
  ip_len = clib_net_to_host_u16 (ip4->length);
  ASSERT (ip_len <= p->current_length);

  icmp = (icmp46_header_t *) (ip4 + 1);
  if (icmp_to_icmp6_header (icmp, &inner_ip4))
    return -1;

  if (inner_ip4)
    {
      //We have 2 headers to translate.
      //We need to make some room in the middle of the packet
      if (PREDICT_FALSE (ip4_is_fragment (inner_ip4)))
	{
	  //Here it starts getting really tricky
	  //We will add a fragmentation header in the inner packet

	  if (!ip4_is_first_fragment (inner_ip4))
	    {
	      //For now we do not handle unless it is the first fragment
	      //Ideally we should handle the case as we are in slow path already
	      return -1;
	    }

	  vlib_buffer_advance (p,
			       -2 * (sizeof (*ip6) - sizeof (*ip4)) -
			       sizeof (*inner_frag));
	  ip6 = vlib_buffer_get_current (p);
	  memmove (u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4)), ip4,
		   20 + 8);
	  ip4 =
	    (ip4_header_t *) u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4));
	  icmp = (icmp46_header_t *) (ip4 + 1);

	  inner_ip6 =
	    (ip6_header_t *) u8_ptr_add (inner_ip4,
					 sizeof (*ip4) - sizeof (*ip6) -
					 sizeof (*inner_frag));
	  inner_frag =
	    (ip6_frag_hdr_t *) u8_ptr_add (inner_ip6, sizeof (*inner_ip6));
	  ip6->payload_length =
	    u16_net_add (ip4->length,
			 sizeof (*ip6) - 2 * sizeof (*ip4) +
			 sizeof (*inner_frag));
	  inner_frag_id = frag_id_4to6 (inner_ip4->fragment_id);
	  inner_frag_offset = ip4_get_fragment_offset (inner_ip4);
	  inner_frag_more =
	    ! !(inner_ip4->flags_and_fragment_offset &
		clib_net_to_host_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS));
	}
      else
	{
	  vlib_buffer_advance (p, -2 * (sizeof (*ip6) - sizeof (*ip4)));
	  ip6 = vlib_buffer_get_current (p);
	  memmove (u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4)), ip4,
		   20 + 8);
	  ip4 =
	    (ip4_header_t *) u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4));
	  icmp = (icmp46_header_t *) u8_ptr_add (ip4, sizeof (*ip4));
	  inner_ip6 =
	    (ip6_header_t *) u8_ptr_add (inner_ip4,
					 sizeof (*ip4) - sizeof (*ip6));
	  ip6->payload_length =
	    u16_net_add (ip4->length, sizeof (*ip6) - 2 * sizeof (*ip4));
	  inner_frag = NULL;
	}

      if (PREDICT_TRUE (inner_ip4->protocol == IP_PROTOCOL_TCP))
	{
	  inner_L4_checksum = &((tcp_header_t *) (inner_ip4 + 1))->checksum;
	  *inner_L4_checksum =
	    ip_csum_fold (ip_csum_sub_even
			  (*inner_L4_checksum,
			   *((u64 *) (&inner_ip4->src_address))));
	}
      else if (PREDICT_TRUE (inner_ip4->protocol == IP_PROTOCOL_UDP))
	{
	  inner_L4_checksum = &((udp_header_t *) (inner_ip4 + 1))->checksum;
	  if (*inner_L4_checksum)
	    *inner_L4_checksum =
	      ip_csum_fold (ip_csum_sub_even
			    (*inner_L4_checksum,
			     *((u64 *) (&inner_ip4->src_address))));
	}
      else if (inner_ip4->protocol == IP_PROTOCOL_ICMP)
	{
	  //We have an ICMP inside an ICMP
	  //It needs to be translated, but not for error ICMP messages
	  icmp46_header_t *inner_icmp = (icmp46_header_t *) (inner_ip4 + 1);
	  //Only types ICMP4_echo_request and ICMP4_echo_reply are handled by icmp_to_icmp6_header
	  inner_icmp->type = (inner_icmp->type == ICMP4_echo_request) ?
	    ICMP6_echo_request : ICMP6_echo_reply;
	  inner_L4_checksum = &inner_icmp->checksum;
	  inner_ip4->protocol = IP_PROTOCOL_ICMP6;
	}
      else
	{
	  /* To shut up Coverity */
	  os_panic ();
	}

      inner_ip6->ip_version_traffic_class_and_flow_label =
	clib_host_to_net_u32 ((6 << 28) + (inner_ip4->tos << 20));
      inner_ip6->payload_length =
	u16_net_add (inner_ip4->length, -sizeof (*inner_ip4));
      inner_ip6->hop_limit = inner_ip4->ttl;
      inner_ip6->protocol = inner_ip4->protocol;

      if ((rv = inner_fn (p, inner_ip4, inner_ip6, inner_ctx)) != 0)
	return rv;

      if (PREDICT_FALSE (inner_frag != NULL))
	{
	  inner_frag->next_hdr = inner_ip6->protocol;
	  inner_frag->identification = inner_frag_id;
	  inner_frag->rsv = 0;
	  inner_frag->fragment_offset_and_more =
	    ip6_frag_hdr_offset_and_more (inner_frag_offset, inner_frag_more);
	  inner_ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION;
	  inner_ip6->payload_length =
	    clib_host_to_net_u16 (clib_net_to_host_u16
				  (inner_ip6->payload_length) +
				  sizeof (*inner_frag));
	}

      csum = *inner_L4_checksum;
      if (inner_ip6->protocol == IP_PROTOCOL_ICMP6)
	{
	  //Recompute ICMP checksum
	  icmp46_header_t *inner_icmp = (icmp46_header_t *) (inner_ip4 + 1);

	  inner_icmp->checksum = 0;
	  csum = ip_csum_with_carry (0, inner_ip6->payload_length);
	  csum =
	    ip_csum_with_carry (csum,
				clib_host_to_net_u16 (inner_ip6->protocol));
	  csum = ip_csum_with_carry (csum, inner_ip6->src_address.as_u64[0]);
	  csum = ip_csum_with_carry (csum, inner_ip6->src_address.as_u64[1]);
	  csum = ip_csum_with_carry (csum, inner_ip6->dst_address.as_u64[0]);
	  csum = ip_csum_with_carry (csum, inner_ip6->dst_address.as_u64[1]);
	  csum =
	    ip_incremental_checksum (csum, inner_icmp,
				     clib_net_to_host_u16
				     (inner_ip6->payload_length));
	  inner_icmp->checksum = ~ip_csum_fold (csum);
	}
      else
	{
	  /* UDP checksum is optional */
	  if (csum)
	    {
	      csum =
		ip_csum_add_even (csum, inner_ip6->src_address.as_u64[0]);
	      csum =
		ip_csum_add_even (csum, inner_ip6->src_address.as_u64[1]);
	      csum =
		ip_csum_add_even (csum, inner_ip6->dst_address.as_u64[0]);
	      csum =
		ip_csum_add_even (csum, inner_ip6->dst_address.as_u64[1]);
	      *inner_L4_checksum = ip_csum_fold (csum);
	    }
	}
    }
  else
    {
      if (PREDICT_FALSE (ip4->flags_and_fragment_offset &
			 clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS)))
	{
	  vlib_buffer_advance (p, sizeof (*ip4) - sizeof (*ip6) -
			       sizeof (*outer_frag));
	  ip6 = vlib_buffer_get_current (p);
	  outer_frag = (ip6_frag_hdr_t *) (ip6 + 1);
	  outer_frag_id = frag_id_4to6 (ip4->fragment_id);
	}
      else
	{
	  vlib_buffer_advance (p, sizeof (*ip4) - sizeof (*ip6));
	  ip6 = vlib_buffer_get_current (p);
	}
      ip6->payload_length =
	clib_host_to_net_u16 (clib_net_to_host_u16 (ip4->length) -
			      sizeof (*ip4));
    }

  //Translate outer IPv6
  ip6->ip_version_traffic_class_and_flow_label =
    clib_host_to_net_u32 ((6 << 28) + (ip4->tos << 20));

  ip6->hop_limit = ip4->ttl;
  ip6->protocol = IP_PROTOCOL_ICMP6;

  if ((rv = fn (p, ip4, ip6, ctx)) != 0)
    return rv;

  if (PREDICT_FALSE (outer_frag != NULL))
    {
      outer_frag->next_hdr = ip6->protocol;
      outer_frag->identification = outer_frag_id;
      outer_frag->rsv = 0;
      outer_frag->fragment_offset_and_more = ip6_frag_hdr_offset_and_more (0, 1);
      ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION;
      ip6->payload_length = u16_net_add (ip6->payload_length,
					 sizeof (*outer_frag));
    }

  //Truncate when ICMPv6 error message exceeds the minimal IPv6 MTU
  if (p->current_length > 1280 && icmp->type < 128)
    {
      ip6->payload_length = clib_host_to_net_u16 (1280 - sizeof (*ip6));
      p->current_length = 1280;	//Looks too simple to be correct...
    }

  //Recompute ICMP checksum
  icmp->checksum = 0;
  csum = ip_csum_with_carry (0, ip6->payload_length);
  csum = ip_csum_with_carry (csum, clib_host_to_net_u16 (ip6->protocol));
  csum = ip_csum_with_carry (csum, ip6->src_address.as_u64[0]);
  csum = ip_csum_with_carry (csum, ip6->src_address.as_u64[1]);
  csum = ip_csum_with_carry (csum, ip6->dst_address.as_u64[0]);
  csum = ip_csum_with_carry (csum, ip6->dst_address.as_u64[1]);
  csum =
    ip_incremental_checksum (csum, icmp,
			     clib_net_to_host_u16 (ip6->payload_length));
  icmp->checksum = ~ip_csum_fold (csum);

  return 0;
}

#endif /* __included_ip4_to_ip6_h__ */