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nuttx/net/sixlowpan/sixlowpan_hc06.c

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/****************************************************************************
* net/sixlowpan/sixlowpan_hc06.c
* 6lowpan HC06 implementation (draft-ietf-6lowpan-hc-06)
*
* Copyright (C) 2017, Gregory Nutt, all rights reserved
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Derives from Contiki:
*
* Copyright (c) 2008, Swedish Institute of Computer Science.
* All rights reserved.
* Authors: Adam Dunkels <adam@sics.se>
* Nicolas Tsiftes <nvt@sics.se>
* Niclas Finne <nfi@sics.se>
* Mathilde Durvy <mdurvy@cisco.com>
* Julien Abeille <jabeille@cisco.com>
* Joakim Eriksson <joakime@sics.se>
* Joel Hoglund <joel@sics.se>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
****************************************************************************/
/* FOR HC-06 COMPLIANCE TODO:
*
* -Add compression options to UDP, currently only supports
* both ports compressed or both ports elided
* -Verify TC/FL compression works
* -Add stateless multicast option
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <debug.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include "sixlowpan/sixlowpan_internal.h"
#ifdef CONFIG_NET_6LOWPAN_COMPRESSION_HC06
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define IPv6BUF(ieee) \
((FAR struct ipv6_hdr_s *)&(ieee)->i_dev.d_buf)
#define UDPIPv6BUF(ieee) \
((FAR struct udp_hdr_s *)&(ieee)->i_dev.d_buf[IPv6_HDRLEN])
/****************************************************************************
* Private Types
****************************************************************************/
/* An address context for IPHC address compression each context can have up
* to 8 bytes
*/
struct sixlowpan_addrcontext_s
{
uint8_t used; /* Possibly use as prefix-length */
uint8_t number;
uint8_t prefix[8];
};
/****************************************************************************
* Private Data
****************************************************************************/
/* HC06 specific variables **************************************************/
/* Use of global variables simplifies the logic and is safe in the multi-
* device environment because access is serialized via the network lock.
*
* But note that state may NOT be preserved from packet-to-packet.
*/
#if CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 0
/* Addresses contexts for IPHC. */
static struct sixlowpan_addrcontext_s
g_hc06_addrcontexts[CONFIG_NET_6LOWPAN_MAXADDRCONTEXT];
#endif
/* Pointer to the byte where to write next inline field. */
static FAR uint8_t *g_hc06ptr;
/* Constant Data ************************************************************/
/* Uncompression of linklocal
*
* 0 -> 16 bytes from packet
* 1 -> 2 bytes from prefix - bunch of zeroes and 8 from packet
* 2 -> 2 bytes from prefix - 0000::00ff:fe00:XXXX from packet
* 3 -> 2 bytes from prefix - infer 8 bytes from MAC address
*
* NOTE: => the uncompress function does change 0xf to 0x10
* NOTE: 0x00 => no-autoconfig => unspecified
*/
static const uint8_t g_unc_llconf[] = { 0x0f, 0x28, 0x22, 0x20 };
/* Uncompression of ctx-based
*
* 0 -> 0 bits from packet [unspecified / reserved]
* 1 -> 8 bytes from prefix - bunch of zeroes and 8 from packet
* 2 -> 8 bytes from prefix - 0000::00ff:fe00:XXXX + 2 from packet
* 3 -> 8 bytes from prefix - infer 8 bytes from MAC address
*/
static const uint8_t g_unc_ctxconf[] = { 0x00, 0x88, 0x82, 0x80 };
/* Uncompression of ctx-based
*
* 0 -> 0 bits from packet
* 1 -> 2 bytes from prefix - bunch of zeroes 5 from packet
* 2 -> 2 bytes from prefix - zeroes + 3 from packet
* 3 -> 2 bytes from prefix - infer 1 bytes from MAC address
*/
static const uint8_t g_unc_mxconf[] = { 0x0f, 0x25, 0x23, 0x21 };
/* Link local prefix */
static const uint8_t g_llprefix[] = { 0xfe, 0x80 };
/* TTL uncompression values */
static const uint8_t g_ttl_values[] = { 0, 1, 64, 255 };
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: find_addrcontext_bynumber
*
* Description:
* Find the address context with the given number.
*
****************************************************************************/
static FAR struct sixlowpan_addrcontext_s *
find_addrcontext_bynumber(uint8_t number)
{
/* Remove code to avoid warnings and save flash if no address context is
* used.
*/
#if CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 0
int i;
for (i = 0; i < CONFIG_NET_6LOWPAN_MAXADDRCONTEXT; i++)
{
if ((g_hc06_addrcontexts[i].used == 1) &&
g_hc06_addrcontexts[i].number == number)
{
return &g_hc06_addrcontexts[i];
}
}
#endif /* CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 0 */
return NULL;
}
/****************************************************************************
* Name: find_addrcontext_bynumber
*
* Description:
* Find the address context corresponding to the prefix ipaddr.
*
****************************************************************************/
static FAR struct sixlowpan_addrcontext_s *
find_addrcontext_byprefix(FAR const net_ipv6addr_t ipaddr)
{
#if CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 0
int i;
/* Remove code to avoid warnings and save flash if no address context is used */
for (i = 0; i < CONFIG_NET_6LOWPAN_MAXADDRCONTEXT; i++)
{
if ((g_hc06_addrcontexts[i].used == 1) &&
net_ipv6addr_prefixcmp(&g_hc06_addrcontexts[i].prefix, ipaddr, 64))
{
return &g_hc06_addrcontexts[i];
}
}
#endif /* CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 0 */
return NULL;
}
/****************************************************************************
* Name: uncompress_addr
*
* Description:
* Uncompress addresses based on a prefix and a postfix with zeroes in
* between. If the postfix is zero in length it will use the link address
* to configure the IP address (autoconf style).
*
* prefpost takes a byte where the first nibble specify prefix count
* and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
*
****************************************************************************/
static uint8_t compress_addr_64(FAR const net_ipv6addr_t ipaddr,
FAR const struct rimeaddr_s *macaddr,
uint8_t bitpos)
{
if (sixlowpan_ismacbased(ipaddr, macaddr))
{
return 3 << bitpos; /* 0-bits */
}
else if (SIXLOWPAN_IS_IID_16BIT_COMPRESSABLE(ipaddr))
{
/* Compress IID to 16 bits xxxx::0000:00ff:fe00:XXXX */
memcpy(g_hc06ptr, &ipaddr[7], 2);
g_hc06ptr += 2;
return 2 << bitpos; /* 16-bits */
}
else
{
/* Do not compress IID => xxxx::IID */
memcpy(g_hc06ptr, &ipaddr[4], 8);
g_hc06ptr += 8;
return 1 << bitpos; /* 64-bits */
}
}
/****************************************************************************
* Name: uncompress_addr
*
* Description:
* Uncompress addresses based on a prefix and a postfix with zeroes in
* between. If the postfix is zero in length it will use the link address
* to configure the IP address (autoconf style).
*
* prefpost takes a byte where the first nibble specify prefix count
* and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
*
****************************************************************************/
static void uncompress_addr(FAR net_ipv6addr_t ipaddr, uint8_t const prefix[],
uint8_t prefpost, FAR struct rimeaddr_s *macaddr)
{
uint8_t prefcount = prefpost >> 4;
uint8_t postcount = prefpost & 0x0f;
/* Full nibble 15 => 16 */
prefcount = prefcount == 15 ? 16 : prefcount;
postcount = postcount == 15 ? 16 : postcount;
if (prefcount > 0)
{
memcpy(ipaddr, prefix, prefcount);
}
if (prefcount + postcount < 16)
{
FAR uint8_t *iptr = (FAR uint8_t *)&ipaddr[0];
memset(&iptr[prefcount], 0, 16 - (prefcount + postcount));
}
if (postcount > 0)
{
FAR uint8_t *iptr = (FAR uint8_t *)&ipaddr[0];
memcpy(&iptr[16 - postcount], g_hc06ptr, postcount);
if (postcount == 2 && prefcount < 11)
{
/* 16 bits uncompression => 0000:00ff:fe00:XXXX */
iptr[11] = 0xff;
iptr[12] = 0xfe;
}
g_hc06ptr += postcount;
}
else if (prefcount > 0)
{
/* No IID based configuration if no prefix and no data => unspec */
sixlowpan_ipfromrime(macaddr, ipaddr);
}
ninfo("Uncompressing %d + %d => %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
prefcount, postcount, ipaddr[0], ipaddr[2], ipaddr[3], ipaddr[5],
ipaddr[5], ipaddr[6], ipaddr[7]);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sixlowpan_hc06_initialize
*
* Description:
* sixlowpan_hc06_initialize() is called during OS initialization at power-up
* reset. It is called from the common sixlowpan_initialize() function.
* sixlowpan_hc06_initialize() configures HC06 networking data structures.
* It is called prior to platform-specific driver initialization so that
* the 6loWPAN networking subsystem is prepared to deal with network
* driver initialization actions.
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
void sixlowpan_hc06_initialize(void)
{
#if CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 0
#if CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 1
int i;
#endif
/* Preinitialize any address contexts for better header compression
* (Saves up to 13 bytes per 6lowpan packet).
*/
g_hc06_addrcontexts[0].used = 1;
g_hc06_addrcontexts[0].number = 0;
g_hc06_addrcontexts[0].prefix[0] = CONFIG_NET_6LOWPAN_MAXADDRCONTEXT_PREFIX_0_0;
g_hc06_addrcontexts[0].prefix[1] = CONFIG_NET_6LOWPAN_MAXADDRCONTEXT_PREFIX_0_1;
#if CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 1
for (i = 1; i < CONFIG_NET_6LOWPAN_MAXADDRCONTEXT; i++)
{
#ifdef CONFIG_NET_6LOWPAN_MAXADDRCONTEXT_PREINIT_1
if (i == 1)
{
g_hc06_addrcontexts[1].used = 1;
g_hc06_addrcontexts[1].number = 1;
g_hc06_addrcontexts[1].prefix[0] = CONFIG_NET_6LOWPAN_MAXADDRCONTEXT_PREFIX_1_0;
g_hc06_addrcontexts[1].prefix[1] = CONFIG_NET_6LOWPAN_MAXADDRCONTEXT_PREFIX_1_1;
}
else
#ifdef CONFIG_NET_6LOWPAN_MAXADDRCONTEXT_PREINIT_2
if (i == 2)
{
g_hc06_addrcontexts[2].used = 1;
g_hc06_addrcontexts[2].number = 2;
g_hc06_addrcontexts[2].prefix[0] = CONFIG_NET_6LOWPAN_MAXADDRCONTEXT_PREFIX_2_0;
g_hc06_addrcontexts[2].prefix[1] = CONFIG_NET_6LOWPAN_MAXADDRCONTEXT_PREFIX_2_1;
}
else
#endif /* SIXLOWPAN_CONF_ADDR_CONTEXT_2 */
{
g_hc06_addrcontexts[i].used = 0;
}
#else
g_hc06_addrcontexts[i].used = 0;
#endif /* SIXLOWPAN_CONF_ADDR_CONTEXT_1 */
}
#endif /* CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 1 */
#endif /* CONFIG_NET_6LOWPAN_MAXADDRCONTEXT > 0 */
}
/****************************************************************************
* Name: sixlowpan_compresshdr_hc06
*
* Description:
* Compress IP/UDP header
*
* This function is called by the 6lowpan code to create a compressed
* 6lowpan packet in the frame buffer from a full IPv6 packet.
*
* HC-06 (draft-ietf-6lowpan-hc, version 6)
* http://tools.ietf.org/html/draft-ietf-6lowpan-hc-06
*
* NOTE: sixlowpan_compresshdr_hc06() does not support ISA100_UDP header
* compression
*
* For LOWPAN_UDP compression, we either compress both ports or none.
* General format with LOWPAN_UDP compression is
* 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |0|1|1|TF |N|HLI|C|S|SAM|M|D|DAM| SCI | DCI | comp. IPv6 hdr|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | compressed IPv6 fields ..... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | LOWPAN_UDP | non compressed UDP fields ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | L4 data ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* NOTE: The address context number 00 is reserved for the link local
* prefix. For unicast addresses, if we cannot compress the prefix, we
* neither compress the IID.
*
* Input Parameters:
* ieee - A reference to the IEE802.15.4 network device state
* ipv6 - The IPv6 header to be compressed
* destmac - L2 destination address, needed to compress the IP
* destination field
* iob - The IOB into which the compressed header should be saved.
*
* Returned Value:
* None
*
****************************************************************************/
void sixlowpan_compresshdr_hc06(FAR struct ieee802154_driver_s *ieee,
FAR const struct ipv6_hdr_s *ipv6,
FAR const struct rimeaddr_s *destmac,
FAR struct iob_s *iob)
{
FAR uint8_t *iphc = RIME_IPHC_BUF;
FAR struct sixlowpan_addrcontext_s *addrcontext;
uint8_t iphc0;
uint8_t iphc1;
uint8_t tmp;
ninfodumpbuffer("IPv6 before compression", ipv6, sizeof(ipv6_hdr_s));
g_hc06ptr = g_rimeptr + 2;
/* As we copy some bit-length fields, in the IPHC encoding bytes,
* we sometimes use |=
* If the field is 0, and the current bit value in memory is 1,
* this does not work. We therefore reset the IPHC encoding here
*/
iphc0 = SIXLOWPAN_DISPATCH_IPHC;
iphc1 = 0;
iphc[2] = 0; /* Might not be used - but needs to be cleared */
/* Address handling needs to be made first since it might cause an extra
* byte with [ SCI | DCI ]
*/
/* Check if dest address context exists (for allocating third byte)
*
* TODO: fix this so that it remembers the looked up values for avoiding two
* lookups - or set the lookup values immediately
*/
if (find_addrcontext_byprefix(ipv6->destipaddr) != NULL ||
find_addrcontext_byprefix(ipv6->srcipaddr) != NULL)
{
/* set address context flag and increase g_hc06ptr */
ninfo("Decompressing dest or src ipaddr. Setting CID\n");
iphc1 |= SIXLOWPAN_IPHC_CID;
g_hc06ptr++;
}
/* Traffic class, flow label
*
* If flow label is 0, compress it. If traffic class is 0, compress it
* We have to process both in the same time as the offset of traffic class
* depends on the presence of version and flow label
*/
/* hc06 format of tc is ECN | DSCP , original is DSCP | ECN */
tmp = (ipv6->vtc << 4) | (ipv6->tcf >> 4);
tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
if (((ipv6->tcf & 0x0f) == 0) && (ipv6->flow == 0))
{
/* Flow label can be compressed */
iphc0 |= SIXLOWPAN_IPHC_FL_C;
if (((ipv6->vtc & 0x0f) == 0) && ((ipv6->tcf & 0xf0) == 0))
{
/* Compress (elide) all */
iphc0 |= SIXLOWPAN_IPHC_TC_C;
}
else
{
/* Sompress only the flow label */
*g_hc06ptr = tmp;
g_hc06ptr += 1;
}
}
else
{
/* Flow label cannot be compressed */
if (((ipv6->vtc & 0x0f) == 0) && ((ipv6->tcf & 0xF0) == 0))
{
/* Compress only traffic class */
iphc0 |= SIXLOWPAN_IPHC_TC_C;
*g_hc06ptr = (tmp & 0xc0) | (ipv6->tcf & 0x0f);
memcpy(g_hc06ptr + 1, &ipv6->flow, 2);
g_hc06ptr += 3;
}
else
{
/* Compress nothing */
memcpy(g_hc06ptr, &ipv6->vtc, 4);
/* But replace the top byte with the new ECN | DSCP format */
*g_hc06ptr = tmp;
g_hc06ptr += 4;
}
}
/* Note that the payload length is always compressed */
/* Next header. We compress it if UDP */
#if CONFIG_NET_UDP || UIP_CONF_ROUTER
if (ipv6->proto == IP_PROTO_UDP)
{
iphc0 |= SIXLOWPAN_IPHC_NH_C;
}
#endif /* CONFIG_NET_UDP */
if ((iphc0 & SIXLOWPAN_IPHC_NH_C) == 0)
{
*g_hc06ptr = ipv6->proto;
g_hc06ptr += 1;
}
/* Hop limit
*
* if 1: compress, encoding is 01
* if 64: compress, encoding is 10
* if 255: compress, encoding is 11
* else do not compress
*/
switch (ipv6->ttl)
{
case 1:
iphc0 |= SIXLOWPAN_IPHC_TTL_1;
break;
case 64:
iphc0 |= SIXLOWPAN_IPHC_TTL_64;
break;
case 255:
iphc0 |= SIXLOWPAN_IPHC_TTL_255;
break;
default:
*g_hc06ptr = ipv6->ttl;
g_hc06ptr += 1;
break;
}
/* Source address - cannot be multicast */
if (net_is_addr_unspecified(ipv6->srcipaddr))
{
ninfo("Compressing unspecified. Setting SAC\n");
iphc1 |= SIXLOWPAN_IPHC_SAC;
iphc1 |= SIXLOWPAN_IPHC_SAM_00;
}
else if ((addrcontext = find_addrcontext_byprefix(ipv6->srcipaddr)) != NULL)
{
/* Elide the prefix - indicate by CID and set address context + SAC */
ninfo("Compressing src with address context. Setting CID and SAC context: %d\n",
addrcontext->number);
iphc1 |= SIXLOWPAN_IPHC_CID | SIXLOWPAN_IPHC_SAC;
iphc[2] |= addrcontext->number << 4;
/* Compession compare with this nodes address (source) */
iphc1 |= compress_addr_64(ipv6->srcipaddr, &ieee->i_nodeaddr,
SIXLOWPAN_IPHC_SAM_BIT);
/* No address context found for this address */
}
else if (net_is_addr_linklocal(ipv6->srcipaddr) &&
ipv6->destipaddr[1] == 0 && ipv6->destipaddr[2] == 0 &&
ipv6->destipaddr[3] == 0)
{
iphc1 |= compress_addr_64(ipv6->srcipaddr, &ieee->i_nodeaddr,
SIXLOWPAN_IPHC_SAM_BIT);
}
else
{
/* Send the full address => SAC = 0, SAM = 00 */
iphc1 |= SIXLOWPAN_IPHC_SAM_00; /* 128-bits */
memcpy(g_hc06ptr, ipv6->srcipaddr, 16);
g_hc06ptr += 16;
}
/* Destination address */
if (net_is_addr_mcast(ipv6->destipaddr))
{
/* Address is multicast, try to compress */
iphc1 |= SIXLOWPAN_IPHC_M;
if (SIXLOWPAN_IS_MCASTADDR_COMPRESSABLE8(ipv6->destipaddr))
{
iphc1 |= SIXLOWPAN_IPHC_DAM_11;
/* Use last byte */
*g_hc06ptr = ipv6->destipaddr[7] & 0x00ff;
g_hc06ptr += 1;
}
else if (SIXLOWPAN_IS_MCASTADDR_COMPRESSABLE32(ipv6->destipaddr))
{
FAR uint8_t *iptr = (FAR uint8_t *)ipv6->destipaddr;
iphc1 |= SIXLOWPAN_IPHC_DAM_10;
/* Second byte + the last three */
*g_hc06ptr = iptr[1];
memcpy(g_hc06ptr + 1, &iptr[13], 3);
g_hc06ptr += 4;
}
else if (SIXLOWPAN_IS_MCASTADDR_COMPRESSABLE48(ipv6->destipaddr))
{
FAR uint8_t *iptr = (FAR uint8_t *)ipv6->destipaddr;
iphc1 |= SIXLOWPAN_IPHC_DAM_01;
/* Second byte + the last five */
*g_hc06ptr = iptr[1];
memcpy(g_hc06ptr + 1, &iptr[11], 5);
g_hc06ptr += 6;
}
else
{
iphc1 |= SIXLOWPAN_IPHC_DAM_00;
/* Full address */
memcpy(g_hc06ptr, ipv6->destipaddr, 16);
g_hc06ptr += 16;
}
}
else
{
/* Address is unicast, try to compress */
if ((addrcontext = find_addrcontext_byprefix(ipv6->destipaddr)) != NULL)
{
/* Elide the prefix */
iphc1 |= SIXLOWPAN_IPHC_DAC;
iphc[2] |= addrcontext->number;
/* Compession compare with link adress (destination) */
iphc1 |= compress_addr_64(ipv6->destipaddr, destmac,
SIXLOWPAN_IPHC_DAM_BIT);
/* No address context found for this address */
}
else if (net_is_addr_linklocal(ipv6->destipaddr) &&
ipv6->destipaddr[1] == 0 && ipv6->destipaddr[2] == 0 &&
ipv6->destipaddr[3] == 0)
{
iphc1 |= compress_addr_64(ipv6->destipaddr, destmac,
SIXLOWPAN_IPHC_DAM_BIT);
}
else
{
/* Send the full address */
iphc1 |= SIXLOWPAN_IPHC_DAM_00; /* 128-bits */
memcpy(g_hc06ptr, ipv6->destipaddr, 16);
g_hc06ptr += 16;
}
}
g_uncomp_hdrlen = IPv6_HDRLEN;
#if CONFIG_NET_UDP
/* UDP header compression */
if (ipv6->proto == IP_PROTO_UDP)
{
FAR struct udp_hdr_s *udp = UDPIPv6BUF(ieee);
ninfo("Uncompressed UDP ports on send side: %x, %x\n",
ntohs(udp->srcport), ntohs(udp->destport));
/* Mask out the last 4 bits can be used as a mask */
if (((ntohs(udp->srcport) & 0xfff0) == SIXLOWPAN_UDP_4_BIT_PORT_MIN) &&
((ntohs(udp->destport) & 0xfff0) == SIXLOWPAN_UDP_4_BIT_PORT_MIN))
{
/* We can compress 12 bits of both source and dest */
*g_hc06ptr = SIXLOWPAN_NHC_UDP_CS_P_11;
ninfo("Remove 12b of both source & dest with prefix 0xfob\n");
*(g_hc06ptr + 1) =
(uint8_t)((ntohs(udp->srcport) - SIXLOWPAN_UDP_4_BIT_PORT_MIN) << 4) +
(uint8_t)((ntohs(udp->destport) - SIXLOWPAN_UDP_4_BIT_PORT_MIN));
g_hc06ptr += 2;
}
else if ((ntohs(udp->destport) & 0xff00) ==
SIXLOWPAN_UDP_8_BIT_PORT_MIN)
{
/* We can compress 8 bits of dest, leave source. */
*g_hc06ptr = SIXLOWPAN_NHC_UDP_CS_P_01;
ninfo("Leave source, remove 8 bits of dest with prefix 0xF0\n");
memcpy(g_hc06ptr + 1, &udp->srcport, 2);
*(g_hc06ptr + 3) =
(uint8_t) ((ntohs(udp->destport) -
SIXLOWPAN_UDP_8_BIT_PORT_MIN));
g_hc06ptr += 4;
}
else if ((ntohs(udp->srcport) & 0xff00) ==
SIXLOWPAN_UDP_8_BIT_PORT_MIN)
{
/* We can compress 8 bits of src, leave dest. Copy compressed port */
*g_hc06ptr = SIXLOWPAN_NHC_UDP_CS_P_10;
ninfo("Remove 8 bits of source with prefix 0xF0, leave dest. hch: %u\n",
*g_hc06ptr);
*(g_hc06ptr + 1) =
(uint8_t)((ntohs(udp->srcport) - SIXLOWPAN_UDP_8_BIT_PORT_MIN));
memcpy(g_hc06ptr + 2, &udp->destport, 2);
g_hc06ptr += 4;
}
else
{
/* we cannot compress. Copy uncompressed ports, full checksum */
*g_hc06ptr = SIXLOWPAN_NHC_UDP_CS_P_00;
nwarn("WARNING: Cannot compress headers\n");
memcpy(g_hc06ptr + 1, &udp->srcport, 4);
g_hc06ptr += 5;
}
/* Always inline the checksum */
if (1)
{
memcpy(g_hc06ptr, &udp->udpchksum, 2);
g_hc06ptr += 2;
}
g_uncomp_hdrlen += UDP_HDRLEN;
}
#endif /* CONFIG_NET_UDP */
/* Before the g_rime_hdrlen operation */
iphc[0] = iphc0;
iphc[1] = iphc1;
g_rime_hdrlen = g_hc06ptr - g_rimeptr;
return;
}
/****************************************************************************
* Name: sixlowpan_hc06_initialize
*
* Description:
* Uncompress HC06 (i.e., IPHC and LOWPAN_UDP) headers and put them in
* sixlowpan_buf
*
* This function is called by the input function when the dispatch is HC06.
* We process the packet in the rime buffer, uncompress the header fields,
* and copy the result in the sixlowpan buffer. At the end of the
* decompression, g_rime_hdrlen and g_uncompressed_hdrlen are set to the
* appropriate values
*
* Input Parmeters:
* ieee - A reference to the IEE802.15.4 network device state
* iplen - Equal to 0 if the packet is not a fragment (IP length is then
* inferred from the L2 length), non 0 if the packet is a first
* fragment.
*
* Returned Value:
* None
*
****************************************************************************/
void sixlowpan_uncompresshdr_hc06(FAR struct ieee802154_driver_s *ieee,
uint16_t iplen)
{
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF(ieee);
FAR uint8_t *iphc = RIME_IPHC_BUF;
uint8_t iphc0;
uint8_t iphc1;
uint8_t tmp;
/* At least two byte will be used for the encoding */
g_hc06ptr = g_rimeptr + g_rime_hdrlen + 2;
iphc0 = iphc[0];
iphc1 = iphc[1];
/* Another if the CID flag is set */
if (iphc1 & SIXLOWPAN_IPHC_CID)
{
ninfo("IPHC: CID flag set - increase header with one\n");
g_hc06ptr++;
}
/* Traffic class and flow label */
if ((iphc0 & SIXLOWPAN_IPHC_FL_C) == 0)
{
/* Flow label are carried inline */
if ((iphc0 & SIXLOWPAN_IPHC_TC_C) == 0)
{
/* Traffic class is carried inline */
memcpy(&ipv6->tcf, g_hc06ptr + 1, 3);
tmp = *g_hc06ptr;
g_hc06ptr += 4;
/* hc06 format of tc is ECN | DSCP , original is DSCP | ECN */
/* set version, pick highest DSCP bits and set in vtc */
ipv6->vtc = 0x60 | ((tmp >> 2) & 0x0f);
/* ECN rolled down two steps + lowest DSCP bits at top two bits */
ipv6->tcf = ((tmp >> 2) & 0x30) | (tmp << 6) | (ipv6->tcf & 0x0f);
}
else
{
/* Traffic class is compressed (set version and no TC) */
ipv6->vtc = 0x60;
/* Highest flow label bits + ECN bits */
ipv6->tcf = (*g_hc06ptr & 0x0f) | ((*g_hc06ptr >> 2) & 0x30);
memcpy(&ipv6->flow, g_hc06ptr + 1, 2);
g_hc06ptr += 3;
}
}
else
{
/* Version is always 6! */
/* Version and flow label are compressed */
if ((iphc0 & SIXLOWPAN_IPHC_TC_C) == 0)
{
/* Traffic class is inline */
ipv6->vtc = 0x60 | ((*g_hc06ptr >> 2) & 0x0f);
ipv6->tcf = ((*g_hc06ptr << 6) & 0xC0) | ((*g_hc06ptr >> 2) & 0x30);
ipv6->flow = 0;
g_hc06ptr += 1;
}
else
{
/* Traffic class is compressed */
ipv6->vtc = 0x60;
ipv6->tcf = 0;
ipv6->flow = 0;
}
}
/* Next Header */
if ((iphc0 & SIXLOWPAN_IPHC_NH_C) == 0)
{
/* Next header is carried inline */
ipv6->proto = *g_hc06ptr;
ninfo("Next header inline: %d\n", ipv6->proto);
g_hc06ptr += 1;
}
/* Hop limit */
if ((iphc0 & 0x03) != SIXLOWPAN_IPHC_TTL_I)
{
ipv6->ttl = g_ttl_values[iphc0 & 0x03];
}
else
{
ipv6->ttl = *g_hc06ptr;
g_hc06ptr += 1;
}
/* Put the source address compression mode SAM in the tmp var */
tmp = ((iphc1 & SIXLOWPAN_IPHC_SAM_11) >> SIXLOWPAN_IPHC_SAM_BIT) & 0x03;
/* Address context based compression */
if (iphc1 & SIXLOWPAN_IPHC_SAC)
{
FAR struct sixlowpan_addrcontext_s *addrcontext;
uint8_t sci = (iphc1 & SIXLOWPAN_IPHC_CID) ? iphc[2] >> 4 : 0;
/* Source address - check address context != NULL only if SAM bits are != 0 */
if (tmp != 0)
{
addrcontext = find_addrcontext_bynumber(sci);
if (addrcontext == NULL)
{
nerr("ERROR: Address context not found\n");
return;
}
}
/* If tmp == 0 we do not have a Address context and therefore no prefix */
uncompress_addr(ipv6->srcipaddr,
tmp != 0 ? addrcontext->prefix : NULL, g_unc_ctxconf[tmp],
(FAR struct rimeaddr_s *)&g_pktaddrs[PACKETBUF_ADDR_SENDER]);
}
else
{
/* No compression and link local */
uncompress_addr(ipv6->srcipaddr, g_llprefix, g_unc_llconf[tmp],
(FAR struct rimeaddr_s *)&g_pktaddrs[PACKETBUF_ADDR_SENDER]);
}
/* Destination address */
/* put the destination address compression mode into tmp */
tmp = ((iphc1 & SIXLOWPAN_IPHC_DAM_11) >> SIXLOWPAN_IPHC_DAM_BIT) & 0x03;
/* Multicast compression */
if (iphc1 & SIXLOWPAN_IPHC_M)
{
/* Address context based multicast compression */
if (iphc1 & SIXLOWPAN_IPHC_DAC)
{
/* TODO: implement this */
}
else
{
/* non-address context based multicast compression
*
* DAM_00: 128 bits
* DAM_01: 48 bits FFXX::00XX:XXXX:XXXX
* DAM_10: 32 bits FFXX::00XX:XXXX
* DAM_11: 8 bits FF02::00XX
*/
uint8_t prefix[] = { 0xff, 0x02 };
if (tmp > 0 && tmp < 3)
{
prefix[1] = *g_hc06ptr;
g_hc06ptr++;
}
uncompress_addr(ipv6->destipaddr, prefix, g_unc_mxconf[tmp], NULL);
}
}
else
{
/* no multicast */
/* Context based */
if (iphc1 & SIXLOWPAN_IPHC_DAC)
{
FAR struct sixlowpan_addrcontext_s *addrcontext;
uint8_t dci = (iphc1 & SIXLOWPAN_IPHC_CID) ? iphc[2] & 0x0f : 0;
addrcontext = find_addrcontext_bynumber(dci);
/* All valid cases below need the address context! */
if (addrcontext == NULL)
{
ninfo("ERROR: Address context not found\n");
return;
}
uncompress_addr(ipv6->destipaddr, addrcontext->prefix, g_unc_ctxconf[tmp],
(FAR struct rimeaddr_s *)&g_pktaddrs[PACKETBUF_ADDR_RECEIVER]);
}
else
{
/* Not address context based => link local M = 0, DAC = 0 - same as SAC */
uncompress_addr(ipv6->destipaddr, g_llprefix, g_unc_llconf[tmp],
(FAR struct rimeaddr_s *)&g_pktaddrs[PACKETBUF_ADDR_RECEIVER]);
}
}
g_uncomp_hdrlen += IPv6_HDRLEN;
/* Next header processing - continued */
if ((iphc0 & SIXLOWPAN_IPHC_NH_C))
{
FAR struct udp_hdr_s *udp = UDPIPv6BUF(ieee);
/* The next header is compressed, NHC is following */
if ((*g_hc06ptr & SIXLOWPAN_NHC_UDP_MASK) == SIXLOWPAN_NHC_UDP_ID)
{
uint8_t checksum_compressed;
ipv6->proto = IP_PROTO_UDP;
checksum_compressed = *g_hc06ptr & SIXLOWPAN_NHC_UDP_CHECKSUMC;
ninfo("Incoming header value: %i\n", *g_hc06ptr);
switch (*g_hc06ptr & SIXLOWPAN_NHC_UDP_CS_P_11)
{
case SIXLOWPAN_NHC_UDP_CS_P_00:
/* 1 byte for NHC, 4 byte for ports, 2 bytes chksum */
memcpy(&udp->srcport, g_hc06ptr + 1, 2);
memcpy(&udp->destport, g_hc06ptr + 3, 2);
ninfo("Uncompressed UDP ports (ptr+5): %x, %x\n",
htons(udp->srcport), htons(udp->destport));
g_hc06ptr += 5;
break;
case SIXLOWPAN_NHC_UDP_CS_P_01:
/* 1 byte for NHC + source 16bit inline, dest = 0xF0 + 8 bit
* inline
*/
ninfo("Decompressing destination\n");
memcpy(&udp->srcport, g_hc06ptr + 1, 2);
udp->destport =
htons(SIXLOWPAN_UDP_8_BIT_PORT_MIN + (*(g_hc06ptr + 3)));
ninfo("Uncompressed UDP ports (ptr+4): %x, %x\n",
htons(udp->srcport), htons(udp->destport));
g_hc06ptr += 4;
break;
case SIXLOWPAN_NHC_UDP_CS_P_10:
/* 1 byte for NHC + source = 0xF0 + 8bit inline, dest = 16 bit
* inline
*/
ninfo("Decompressing source\n");
udp->srcport =
htons(SIXLOWPAN_UDP_8_BIT_PORT_MIN + (*(g_hc06ptr + 1)));
memcpy(&udp->destport, g_hc06ptr + 2, 2);
ninfo("Uncompressed UDP ports (ptr+4): %x, %x\n",
htons(udp->srcport), htons(udp->destport));
g_hc06ptr += 4;
break;
case SIXLOWPAN_NHC_UDP_CS_P_11:
/* 1 byte for NHC, 1 byte for ports */
udp->srcport =
htons(SIXLOWPAN_UDP_4_BIT_PORT_MIN +
(*(g_hc06ptr + 1) >> 4));
udp->destport =
htons(SIXLOWPAN_UDP_4_BIT_PORT_MIN +
((*(g_hc06ptr + 1)) & 0x0f));
ninfo("Uncompressed UDP ports (ptr+2): %x, %x\n",
htons(udp->srcport), htons(udp->destport));
g_hc06ptr += 2;
break;
default:
nerr("ERROR: Error unsupported UDP compression\n");
return;
}
if (!checksum_compressed)
{
/* Has_checksum, default */
memcpy(&udp->udpchksum, g_hc06ptr, 2);
g_hc06ptr += 2;
ninfo("Checksum included\n");
}
else
{
nwarn("WARNING: checksum *NOT* included\n");
}
g_uncomp_hdrlen += UDP_HDRLEN;
}
}
g_rime_hdrlen = g_hc06ptr - g_rimeptr;
/* IP length field. */
if (iplen == 0)
{
/* This is not a fragmented packet */
ipv6->len[0] = 0;
ipv6->len[1] = ieee->i_dev.d_len - g_rime_hdrlen + g_uncomp_hdrlen - IPv6_HDRLEN;
}
else
{
/* This is a first fragment */
ipv6->len[0] = (iplen - IPv6_HDRLEN) >> 8;
ipv6->len[1] = (iplen - IPv6_HDRLEN) & 0x00ff;
}
/* Length field in UDP header */
if (ipv6->proto == IP_PROTO_UDP)
{
FAR struct udp_hdr_s *udp = UDPIPv6BUF(ieee);
memcpy(&udp->udplen, &ipv6->len[0], 2);
}
}
#endif /* CONFIG_NET_6LOWPAN_COMPRESSION_HC06 */
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