nuttx/net/sixlowpan/sixlowpan_utils.c
2017-04-01 15:05:38 -06:00

188 lines
6.7 KiB
C

/****************************************************************************
* net/sixlowpan/sixlowpan_utils.c
*
* Copyright (C) 2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Copyright (C) 2017, Gregory Nutt, all rights reserved
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Derives from logic in 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.
*
****************************************************************************/
/* Frame Organization. The IOB data is retained in the io_data[] field of the
* IOB structure like:
*
* Content Offset
* +------------------+ 0
* | Frame Header |
* +------------------+ g_dataoffset
* | Procotol Headers |
* | Data Payload |
* +------------------+ iob->io_len
* | Unused |
* +------------------+ CONFIG_NET_6LOWPAN_FRAMELEN
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/net/sixlowpan.h>
#include "sixlowpan/sixlowpan_internal.h"
#ifdef CONFIG_NET_6LOWPAN
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sixlowpan_frame_hdralloc
*
* Description:
* Allocate space for a header within the packet buffer (dev->d_buf).
*
****************************************************************************/
int sixlowpan_frame_hdralloc(FAR struct iob_s *iob, int size)
{
if (size <= FRAME_REMAINING(iob))
{
g_dataoffset += size;
iob->io_len += size;
return OK;
}
return -ENOMEM;
}
/****************************************************************************
* Name: sixlowpan_ipfromrime
*
* Description:
* Create a link local IPv6 address from a rime address:
*
* 128 112 96 80 64 48 32 16
* ---- ---- ---- ---- ---- ---- ---- ----
* fe80 0000 0000 0000 xxxx xxxx 0000 0000 2-byte Rime address (VALID?)
* fe80 0000 0000 0000 xxxx xxxx xxxx xxxx 8-byte Rime address
*
****************************************************************************/
void sixlowpan_ipfromrime(FAR const struct rimeaddr_s *rime,
net_ipv6addr_t ipaddr)
{
memset(ipaddr, 0, sizeof(net_ipv6addr_t));
ipaddr[0] = 0xfe80;
/* We consider only links with IEEE EUI-64 identifier or IEEE 48-bit MAC
* addresses. NOTE: that CONFIG_NET_6LOWPAN_RIMEADDR_SIZE may be 2 or
* 8. In the case of 2, we treat the address like an 8 byte address with
* the lower bytes set to zero.
*
* REVISIT: This is just a guess so that I can continue making forward
* progress. What is the correct policy?
*/
memcpy(&ipaddr[4], rime, CONFIG_NET_6LOWPAN_RIMEADDR_SIZE);
ipaddr[4] ^= 0x0200;
}
/****************************************************************************
* Name: sixlowpan_rimefromip
*
* Description:
* Extract the rime address from a link local IPv6 address:
*
* 128 112 96 80 64 48 32 16
* ---- ---- ---- ---- ---- ---- ---- ----
* fe80 0000 0000 0000 xxxx 0000 0000 0000 2-byte Rime address (VALID?)
* fe80 0000 0000 0000 xxxx xxxx xxxx xxxx 8-byte Rime address
*
****************************************************************************/
void sixlowpan_rimefromip(const net_ipv6addr_t ipaddr,
FAR struct rimeaddr_s *rime)
{
/* REVISIT: See notes about 2 byte addresses in sixlowpan_ipfromrime() */
DEBUGASSERT(ipaddr[0] == 0xfe80);
memcpy(rime, &ipaddr[4], CONFIG_NET_6LOWPAN_RIMEADDR_SIZE);
rime->u8[0] ^= 0x02;
}
/****************************************************************************
* Name: sixlowpan_ismacbased
*
* Description:
* Extract the rime address from a link local IPv6 address:
*
* 128 112 96 80 64 48 32 16
* ---- ---- ---- ---- ---- ---- ---- ----
* fe80 0000 0000 0000 xxxx 0000 0000 0000 2-byte Rime address (VALID?)
* fe80 0000 0000 0000 xxxx xxxx xxxx xxxx 8-byte Rime address
*
****************************************************************************/
bool sixlowpan_ismacbased(const net_ipv6addr_t ipaddr,
FAR const struct rimeaddr_s *rime)
{
FAR const uint8_t *rimeptr = rime->u8;
#if CONFIG_NET_6LOWPAN_RIMEADDR_SIZE == 2
return ((ipaddr[4] == (GETINT16(rimeptr, 0) ^ 0x0200)) &&
ipaddr[5] == 0 && ipaddr[6] == 0 && ipaddr[7] == 0);
#else /* CONFIG_NET_6LOWPAN_RIMEADDR_SIZE == 8 */
return ((ipaddr[4] == (GETINT16(rimeptr, 0) ^ 0x0200)) &&
ipaddr[5] == GETINT16(rimeptr, 2) &&
ipaddr[6] == GETINT16(rimeptr, 4) &&
ipaddr[7] == GETINT16(rimeptr, 6));
#endif
}
#endif /* CONFIG_NET_6LOWPAN */