blob: 6de0ae3282131a89254e0bebdb027b64c78d3318 [file] [log] [blame]
/**
* @file
* 6LowPAN over BLE output for IPv6 (RFC7668).
*/
/*
* Copyright (c) 2017 Benjamin Aigner
* Copyright (c) 2015 Inico Technologies Ltd. , Author: Ivan Delamer <delamer@inicotech.com>
*
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* Author: Benjamin Aigner <aignerb@technikum-wien.at>
*
* Based on the original 6lowpan implementation of lwIP ( @see 6lowpan.c)
*/
/**
* @defgroup rfc7668if 6LoWPAN over BLE (RFC7668)
* @ingroup netifs
* This file implements a RFC7668 implementation for 6LoWPAN over
* Bluetooth Low Energy. The specification is very similar to 6LoWPAN,
* so most of the code is re-used.
* Compared to 6LoWPAN, much functionality is already implemented in
* lower BLE layers (fragmenting, session management,...).
*
* Usage:
* - add this netif
* - don't add IPv4 addresses (no IPv4 support in RFC7668), pass 'NULL','NULL','NULL'
* - use the BLE to EUI64 conversation util to create an IPv6 link-local address from the BLE MAC (@ref ble_addr_to_eui64)
* - input function: @ref rfc7668_input
* - set the link output function, which transmits output data to an established L2CAP channel
* - If data arrives (HCI event "L2CAP_DATA_PACKET"):
* - allocate a @ref PBUF_RAW buffer
* - let the pbuf struct point to the incoming data or copy it to the buffer
* - call netif->input
*
* @todo:
* - further testing
* - support compression contexts
* - support multiple addresses
* - support multicast
* - support neighbor discovery
*/
#include "netif/lowpan6_ble.h"
#if LWIP_IPV6
#include "lwip/ip.h"
#include "lwip/pbuf.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/nd6.h"
#include "lwip/mem.h"
#include "lwip/udp.h"
#include "lwip/tcpip.h"
#include "lwip/snmp.h"
#include <string.h>
#if LWIP_6LOWPAN_NUM_CONTEXTS > 0
/** context memory, containing IPv6 addresses */
static ip6_addr_t rfc7668_context[LWIP_6LOWPAN_NUM_CONTEXTS];
#else
#define rfc7668_context NULL
#endif
static struct lowpan6_link_addr rfc7668_local_addr;
static struct lowpan6_link_addr rfc7668_peer_addr;
/**
* @ingroup rfc7668if
* convert BT address to EUI64 addr
*
* This method converts a Bluetooth MAC address to an EUI64 address,
* which is used within IPv6 communication
*
* @param dst IPv6 destination space
* @param src BLE MAC address source
* @param public_addr If the LWIP_RFC7668_LINUX_WORKAROUND_PUBLIC_ADDRESS
* option is set, bit 0x02 will be set if param=0 (no public addr); cleared otherwise
*
* @see LWIP_RFC7668_LINUX_WORKAROUND_PUBLIC_ADDRESS
*/
void
ble_addr_to_eui64(uint8_t *dst, const uint8_t *src, int public_addr)
{
/* according to RFC7668 ch 3.2.2. */
memcpy(dst, src, 3);
dst[3] = 0xFF;
dst[4] = 0xFE;
memcpy(&dst[5], &src[3], 3);
#if LWIP_RFC7668_LINUX_WORKAROUND_PUBLIC_ADDRESS
if(public_addr) {
dst[0] &= ~0x02;
} else {
dst[0] |= 0x02;
}
#else
LWIP_UNUSED_ARG(public_addr);
#endif
}
/**
* @ingroup rfc7668if
* convert EUI64 address to Bluetooth MAC addr
*
* This method converts an EUI64 address to a Bluetooth MAC address,
*
* @param dst BLE MAC address destination
* @param src IPv6 source
*
*/
void
eui64_to_ble_addr(uint8_t *dst, const uint8_t *src)
{
/* according to RFC7668 ch 3.2.2. */
memcpy(dst,src,3);
memcpy(&dst[3],&src[5],3);
}
/** Set an address used for stateful compression.
* This expects an address of 6 or 8 bytes.
*/
static err_t
rfc7668_set_addr(struct lowpan6_link_addr *addr, const u8_t *in_addr, size_t in_addr_len, int is_mac_48, int is_public_addr)
{
if ((in_addr == NULL) || (addr == NULL)) {
return ERR_VAL;
}
if (is_mac_48) {
if (in_addr_len != 6) {
return ERR_VAL;
}
addr->addr_len = 8;
ble_addr_to_eui64(addr->addr, in_addr, is_public_addr);
} else {
if (in_addr_len != 8) {
return ERR_VAL;
}
addr->addr_len = 8;
memcpy(addr->addr, in_addr, 8);
}
return ERR_OK;
}
/** Set the local address used for stateful compression.
* This expects an address of 8 bytes.
*/
err_t
rfc7668_set_local_addr_eui64(struct netif *netif, const u8_t *local_addr, size_t local_addr_len)
{
/* netif not used for now, the address is stored globally... */
LWIP_UNUSED_ARG(netif);
return rfc7668_set_addr(&rfc7668_local_addr, local_addr, local_addr_len, 0, 0);
}
/** Set the local address used for stateful compression.
* This expects an address of 6 bytes.
*/
err_t
rfc7668_set_local_addr_mac48(struct netif *netif, const u8_t *local_addr, size_t local_addr_len, int is_public_addr)
{
/* netif not used for now, the address is stored globally... */
LWIP_UNUSED_ARG(netif);
return rfc7668_set_addr(&rfc7668_local_addr, local_addr, local_addr_len, 1, is_public_addr);
}
/** Set the peer address used for stateful compression.
* This expects an address of 8 bytes.
*/
err_t
rfc7668_set_peer_addr_eui64(struct netif *netif, const u8_t *peer_addr, size_t peer_addr_len)
{
/* netif not used for now, the address is stored globally... */
LWIP_UNUSED_ARG(netif);
return rfc7668_set_addr(&rfc7668_peer_addr, peer_addr, peer_addr_len, 0, 0);
}
/** Set the peer address used for stateful compression.
* This expects an address of 6 bytes.
*/
err_t
rfc7668_set_peer_addr_mac48(struct netif *netif, const u8_t *peer_addr, size_t peer_addr_len, int is_public_addr)
{
/* netif not used for now, the address is stored globally... */
LWIP_UNUSED_ARG(netif);
return rfc7668_set_addr(&rfc7668_peer_addr, peer_addr, peer_addr_len, 1, is_public_addr);
}
/** Encapsulate IPv6 frames for BLE transmission
*
* This method implements the IPv6 header compression:
* *) According to RFC6282
* *) See Figure 2, contains base format of bit positions
* *) Fragmentation not necessary (done at L2CAP layer of BLE)
* @note Currently the pbuf allocation uses 256 bytes. If longer packets are used (possible due to MTU=1480Bytes), increase it here!
*
* @param p Pbuf struct, containing the payload data
* @param netif Output network interface. Should be of RFC7668 type
*
* @return Same as netif->output.
*/
static err_t
rfc7668_compress(struct netif *netif, struct pbuf *p)
{
struct pbuf *p_frag;
u16_t remaining_len;
u8_t *buffer;
u8_t lowpan6_header_len;
u8_t hidden_header_len;
err_t err;
LWIP_ASSERT("lowpan6_frag: netif->linkoutput not set", netif->linkoutput != NULL);
#if LWIP_6LOWPAN_IPHC
/* We'll use a dedicated pbuf for building BLE fragments.
* We'll over-allocate it by the bytes saved for header compression.
*/
p_frag = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
if (p_frag == NULL) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
return ERR_MEM;
}
LWIP_ASSERT("this needs a pbuf in one piece", p_frag->len == p_frag->tot_len);
/* Write IP6 header (with IPHC). */
buffer = (u8_t*)p_frag->payload;
err = lowpan6_compress_headers(netif, (u8_t *)p->payload, p->len, buffer, p_frag->len,
&lowpan6_header_len, &hidden_header_len, rfc7668_context, &rfc7668_local_addr, &rfc7668_peer_addr);
if (err != ERR_OK) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
pbuf_free(p_frag);
return err;
}
pbuf_remove_header(p, hidden_header_len);
/* Calculate remaining packet length */
remaining_len = p->tot_len;
/* Copy IPv6 packet */
pbuf_copy_partial(p, buffer + lowpan6_header_len, remaining_len, 0);
/* Calculate frame length */
p_frag->len = p_frag->tot_len = remaining_len + lowpan6_header_len;
/* send the packet */
MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len);
LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG|LWIP_DBG_TRACE, ("rfc7668_output: sending packet %p\n", (void *)p));
err = netif->linkoutput(netif, p_frag);
pbuf_free(p_frag);
return err;
#else /* LWIP_6LOWPAN_IPHC */
/* 6LoWPAN over BLE requires IPHC! */
return ERR_IF;
#endif/* LWIP_6LOWPAN_IPHC */
}
/**
* @ingroup rfc7668if
* Set context id IPv6 address
*
* Store one IPv6 address to a given context id.
*
* @param idx Context id
* @param context IPv6 addr for this context
*
* @return ERR_OK (if everything is fine), ERR_ARG (if the context id is out of range), ERR_VAL (if contexts disabled)
*/
err_t
rfc7668_set_context(u8_t idx, const ip6_addr_t *context)
{
#if LWIP_6LOWPAN_NUM_CONTEXTS > 0
/* check if the ID is possible */
if (idx >= LWIP_6LOWPAN_NUM_CONTEXTS) {
return ERR_ARG;
}
/* copy IPv6 address to context storage */
ip6_addr_set(&rfc7668_context[idx], context);
return ERR_OK;
#else
LWIP_UNUSED_ARG(idx);
LWIP_UNUSED_ARG(context);
return ERR_VAL;
#endif
}
/**
* @ingroup rfc7668if
* Compress outgoing IPv6 packet and pass it on to netif->linkoutput
*
* @param netif The lwIP network interface which the IP packet will be sent on.
* @param q The pbuf(s) containing the IP packet to be sent.
* @param ip6addr The IP address of the packet destination.
*
* @return See rfc7668_compress
*/
err_t
rfc7668_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
{
/* dst ip6addr is not used here, we only have one peer */
LWIP_UNUSED_ARG(ip6addr);
return rfc7668_compress(netif, q);
}
/**
* @ingroup rfc7668if
* Process a received raw payload from an L2CAP channel
*
* @param p the received packet, p->payload pointing to the
* IPv6 header (maybe compressed)
* @param netif the network interface on which the packet was received
*
* @return ERR_OK if everything was fine
*/
err_t
rfc7668_input(struct pbuf * p, struct netif *netif)
{
u8_t * puc;
MIB2_STATS_NETIF_ADD(netif, ifinoctets, p->tot_len);
/* Load first header byte */
puc = (u8_t*)p->payload;
/* no IP header compression */
if (*puc == 0x41) {
LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Completed packet, removing dispatch: 0x%2x \n", *puc));
/* This is a complete IPv6 packet, just skip header byte. */
pbuf_remove_header(p, 1);
/* IPHC header compression */
} else if ((*puc & 0xe0 )== 0x60) {
LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Completed packet, decompress dispatch: 0x%2x \n", *puc));
/* IPv6 headers are compressed using IPHC. */
p = lowpan6_decompress(p, 0, rfc7668_context, &rfc7668_peer_addr, &rfc7668_local_addr);
/* if no pbuf is returned, handle as discarded packet */
if (p == NULL) {
MIB2_STATS_NETIF_INC(netif, ifindiscards);
return ERR_OK;
}
/* invalid header byte, discard */
} else {
LWIP_DEBUGF(LWIP_LOWPAN6_DECOMPRESSION_DEBUG, ("Completed packet, discarding: 0x%2x \n", *puc));
MIB2_STATS_NETIF_INC(netif, ifindiscards);
pbuf_free(p);
return ERR_OK;
}
/* @todo: distinguish unicast/multicast */
MIB2_STATS_NETIF_INC(netif, ifinucastpkts);
#if LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG
{
u16_t i;
LWIP_DEBUGF(LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG, ("IPv6 payload:\n"));
for (i = 0; i < p->len; i++) {
if ((i%4)==0) {
LWIP_DEBUGF(LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG, ("\n"));
}
LWIP_DEBUGF(LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG, ("%2X ", *((uint8_t *)p->payload+i)));
}
LWIP_DEBUGF(LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG, ("\np->len: %d\n", p->len));
}
#endif
/* pass data to ip6_input */
return ip6_input(p, netif);
}
/**
* @ingroup rfc7668if
* Initialize the netif
*
* No flags are used (broadcast not possible, not ethernet, ...)
* The shortname for this netif is "BT"
*
* @param netif the network interface to be initialized as RFC7668 netif
*
* @return ERR_OK if everything went fine
*/
err_t
rfc7668_if_init(struct netif *netif)
{
netif->name[0] = 'b';
netif->name[1] = 't';
/* local function as IPv6 output */
netif->output_ip6 = rfc7668_output;
MIB2_INIT_NETIF(netif, snmp_ifType_other, 0);
/* maximum transfer unit, set according to RFC7668 ch2.4 */
netif->mtu = IP6_MIN_MTU_LENGTH;
/* no flags set (no broadcast, ethernet,...)*/
netif->flags = 0;
/* everything fine */
return ERR_OK;
}
#if !NO_SYS
/**
* Pass a received packet to tcpip_thread for input processing
*
* @param p the received packet, p->payload pointing to the
* IEEE 802.15.4 header.
* @param inp the network interface on which the packet was received
*
* @return see @ref tcpip_inpkt, same return values
*/
err_t
tcpip_rfc7668_input(struct pbuf *p, struct netif *inp)
{
/* send data to upper layer, return the result */
return tcpip_inpkt(p, inp, rfc7668_input);
}
#endif /* !NO_SYS */
#endif /* LWIP_IPV6 */