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Diffstat (limited to 'lwip/src/netif/lowpan6_ble.c')
| -rw-r--r-- | lwip/src/netif/lowpan6_ble.c | 447 |
1 files changed, 447 insertions, 0 deletions
diff --git a/lwip/src/netif/lowpan6_ble.c b/lwip/src/netif/lowpan6_ble.c new file mode 100644 index 0000000..d89816d --- /dev/null +++ b/lwip/src/netif/lowpan6_ble.c @@ -0,0 +1,447 @@ +/** + * @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 = 1280; + + /* 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 */ |