blob: 5e6f0097c1654f37151b5cac1602e3c0aa8d7bb1 [file] [log] [blame]
/**
* @file
*
* 6LowPAN output for IPv6. Uses ND tables for link-layer addressing. Fragments packets to 6LowPAN units.
*
* This implementation aims to conform to IEEE 802.15.4(-2015), RFC 4944 and RFC 6282.
* @todo: RFC 6775.
*/
/*
* Copyright (c) 2015 Inico Technologies Ltd.
* 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.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Ivan Delamer <delamer@inicotech.com>
*
*
* Please coordinate changes and requests with Ivan Delamer
* <delamer@inicotech.com>
*/
/**
* @defgroup sixlowpan 6LoWPAN (RFC4944)
* @ingroup netifs
* 6LowPAN netif implementation
*/
#include "netif/lowpan6.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 "netif/ieee802154.h"
#include <string.h>
#if LWIP_6LOWPAN_802154_HW_CRC
#define LWIP_6LOWPAN_DO_CALC_CRC(buf, len) 0
#else
#define LWIP_6LOWPAN_DO_CALC_CRC(buf, len) LWIP_6LOWPAN_CALC_CRC(buf, len)
#endif
/** This is a helper struct for reassembly of fragments
* (IEEE 802.15.4 limits to 127 bytes)
*/
struct lowpan6_reass_helper {
struct lowpan6_reass_helper *next_packet;
struct pbuf *reass;
struct pbuf *frags;
u8_t timer;
struct lowpan6_link_addr sender_addr;
u16_t datagram_size;
u16_t datagram_tag;
};
/** This struct keeps track of per-netif state */
struct lowpan6_ieee802154_data {
/** fragment reassembly list */
struct lowpan6_reass_helper *reass_list;
#if LWIP_6LOWPAN_NUM_CONTEXTS > 0
/** address context for compression */
ip6_addr_t lowpan6_context[LWIP_6LOWPAN_NUM_CONTEXTS];
#endif
/** Datagram Tag for fragmentation */
u16_t tx_datagram_tag;
/** local PAN ID for IEEE 802.15.4 header */
u16_t ieee_802154_pan_id;
/** Sequence Number for IEEE 802.15.4 transmission */
u8_t tx_frame_seq_num;
};
/* Maximum frame size is 127 bytes minus CRC size */
#define LOWPAN6_MAX_PAYLOAD (127 - 2)
/** Currently, this state is global, since there's only one 6LoWPAN netif */
static struct lowpan6_ieee802154_data lowpan6_data;
#if LWIP_6LOWPAN_NUM_CONTEXTS > 0
#define LWIP_6LOWPAN_CONTEXTS(netif) lowpan6_data.lowpan6_context
#else
#define LWIP_6LOWPAN_CONTEXTS(netif) NULL
#endif
static const struct lowpan6_link_addr ieee_802154_broadcast = {2, {0xff, 0xff}};
#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS
static struct lowpan6_link_addr short_mac_addr = {2, {0, 0}};
#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */
/* IEEE 802.15.4 specific functions: */
/** Write the IEEE 802.15.4 header that encapsulates the 6LoWPAN frame.
* Src and dst PAN IDs are filled with the ID set by @ref lowpan6_set_pan_id.
*
* Since the length is variable:
* @returns the header length
*/
static u8_t
lowpan6_write_iee802154_header(struct ieee_802154_hdr *hdr, const struct lowpan6_link_addr *src,
const struct lowpan6_link_addr *dst)
{
u8_t ieee_header_len;
u8_t *buffer;
u8_t i;
u16_t fc;
fc = IEEE_802154_FC_FT_DATA; /* send data packet (2003 frame version) */
fc |= IEEE_802154_FC_PANID_COMPR; /* set PAN ID compression, for now src and dst PANs are equal */
if (dst != &ieee_802154_broadcast) {
fc |= IEEE_802154_FC_ACK_REQ; /* data packet, no broadcast: ack required. */
}
if (dst->addr_len == 2) {
fc |= IEEE_802154_FC_DST_ADDR_MODE_SHORT;
} else {
LWIP_ASSERT("invalid dst address length", dst->addr_len == 8);
fc |= IEEE_802154_FC_DST_ADDR_MODE_EXT;
}
if (src->addr_len == 2) {
fc |= IEEE_802154_FC_SRC_ADDR_MODE_SHORT;
} else {
LWIP_ASSERT("invalid src address length", src->addr_len == 8);
fc |= IEEE_802154_FC_SRC_ADDR_MODE_EXT;
}
hdr->frame_control = fc;
hdr->sequence_number = lowpan6_data.tx_frame_seq_num++;
hdr->destination_pan_id = lowpan6_data.ieee_802154_pan_id; /* pan id */
buffer = (u8_t *)hdr;
ieee_header_len = 5;
i = dst->addr_len;
/* reverse memcpy of dst addr */
while (i-- > 0) {
buffer[ieee_header_len++] = dst->addr[i];
}
/* Source PAN ID skipped due to PAN ID Compression */
i = src->addr_len;
/* reverse memcpy of src addr */
while (i-- > 0) {
buffer[ieee_header_len++] = src->addr[i];
}
return ieee_header_len;
}
/** Parse the IEEE 802.15.4 header from a pbuf.
* If successful, the header is hidden from the pbuf.
*
* PAN IDs and seuqence number are not checked
*
* @param p input pbuf, p->payload pointing at the IEEE 802.15.4 header
* @param src pointer to source address filled from the header
* @param dest pointer to destination address filled from the header
* @returns ERR_OK if successful
*/
static err_t
lowpan6_parse_iee802154_header(struct pbuf *p, struct lowpan6_link_addr *src,
struct lowpan6_link_addr *dest)
{
u8_t *puc;
s8_t i;
u16_t frame_control, addr_mode;
u16_t datagram_offset;
/* Parse IEEE 802.15.4 header */
puc = (u8_t *)p->payload;
frame_control = puc[0] | (puc[1] << 8);
datagram_offset = 2;
if (frame_control & IEEE_802154_FC_SEQNO_SUPPR) {
if (IEEE_802154_FC_FRAME_VERSION_GET(frame_control) <= 1) {
/* sequence number suppressed, this is not valid for versions 0/1 */
return ERR_VAL;
}
} else {
datagram_offset++;
}
datagram_offset += 2; /* Skip destination PAN ID */
addr_mode = frame_control & IEEE_802154_FC_DST_ADDR_MODE_MASK;
if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_EXT) {
/* extended address (64 bit) */
dest->addr_len = 8;
/* reverse memcpy: */
for (i = 0; i < 8; i++) {
dest->addr[i] = puc[datagram_offset + 7 - i];
}
datagram_offset += 8;
} else if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_SHORT) {
/* short address (16 bit) */
dest->addr_len = 2;
/* reverse memcpy: */
dest->addr[0] = puc[datagram_offset + 1];
dest->addr[1] = puc[datagram_offset];
datagram_offset += 2;
} else {
/* unsupported address mode (do we need "no address"?) */
return ERR_VAL;
}
if (!(frame_control & IEEE_802154_FC_PANID_COMPR)) {
/* No PAN ID compression, skip source PAN ID */
datagram_offset += 2;
}
addr_mode = frame_control & IEEE_802154_FC_SRC_ADDR_MODE_MASK;
if (addr_mode == IEEE_802154_FC_SRC_ADDR_MODE_EXT) {
/* extended address (64 bit) */
src->addr_len = 8;
/* reverse memcpy: */
for (i = 0; i < 8; i++) {
src->addr[i] = puc[datagram_offset + 7 - i];
}
datagram_offset += 8;
} else if (addr_mode == IEEE_802154_FC_DST_ADDR_MODE_SHORT) {
/* short address (16 bit) */
src->addr_len = 2;
src->addr[0] = puc[datagram_offset + 1];
src->addr[1] = puc[datagram_offset];
datagram_offset += 2;
} else {
/* unsupported address mode (do we need "no address"?) */
return ERR_VAL;
}
/* hide IEEE802.15.4 header. */
if (pbuf_remove_header(p, datagram_offset)) {
return ERR_VAL;
}
return ERR_OK;
}
/** Calculate the 16-bit CRC as required by IEEE 802.15.4 */
u16_t
lowpan6_calc_crc(const void* buf, u16_t len)
{
#define CCITT_POLY_16 0x8408U
u16_t i;
u8_t b;
u16_t crc = 0;
const u8_t* p = (const u8_t*)buf;
for (i = 0; i < len; i++) {
u8_t data = *p;
for (b = 0U; b < 8U; b++) {
if (((data ^ crc) & 1) != 0) {
crc = (u16_t)((crc >> 1) ^ CCITT_POLY_16);
} else {
crc = (u16_t)(crc >> 1);
}
data = (u8_t)(data >> 1);
}
p++;
}
return crc;
}
/* Fragmentation specific functions: */
static void
free_reass_datagram(struct lowpan6_reass_helper *lrh)
{
if (lrh->reass) {
pbuf_free(lrh->reass);
}
if (lrh->frags) {
pbuf_free(lrh->frags);
}
mem_free(lrh);
}
/**
* Removes a datagram from the reassembly queue.
**/
static void
dequeue_datagram(struct lowpan6_reass_helper *lrh, struct lowpan6_reass_helper *prev)
{
if (lowpan6_data.reass_list == lrh) {
lowpan6_data.reass_list = lowpan6_data.reass_list->next_packet;
} else {
/* it wasn't the first, so it must have a valid 'prev' */
LWIP_ASSERT("sanity check linked list", prev != NULL);
prev->next_packet = lrh->next_packet;
}
}
/**
* Periodic timer for 6LowPAN functions:
*
* - Remove incomplete/old packets
*/
void
lowpan6_tmr(void)
{
struct lowpan6_reass_helper *lrh, *lrh_next, *lrh_prev = NULL;
lrh = lowpan6_data.reass_list;
while (lrh != NULL) {
lrh_next = lrh->next_packet;
if ((--lrh->timer) == 0) {
dequeue_datagram(lrh, lrh_prev);
free_reass_datagram(lrh);
} else {
lrh_prev = lrh;
}
lrh = lrh_next;
}
}
/*
* Encapsulates data into IEEE 802.15.4 frames.
* Fragments an IPv6 datagram into 6LowPAN units, which fit into IEEE 802.15.4 frames.
* If configured, will compress IPv6 and or UDP headers.
* */
static err_t
lowpan6_frag(struct netif *netif, struct pbuf *p, const struct lowpan6_link_addr *src, const struct lowpan6_link_addr *dst)
{
struct pbuf *p_frag;
u16_t frag_len, remaining_len, max_data_len;
u8_t *buffer;
u8_t ieee_header_len;
u8_t lowpan6_header_len;
u8_t hidden_header_len;
u16_t crc;
u16_t datagram_offset;
err_t err = ERR_IF;
LWIP_ASSERT("lowpan6_frag: netif->linkoutput not set", netif->linkoutput != NULL);
/* We'll use a dedicated pbuf for building 6LowPAN fragments. */
p_frag = pbuf_alloc(PBUF_RAW, 127, 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 IEEE 802.15.4 header. */
buffer = (u8_t *)p_frag->payload;
ieee_header_len = lowpan6_write_iee802154_header((struct ieee_802154_hdr *)buffer, src, dst);
LWIP_ASSERT("ieee_header_len < p_frag->len", ieee_header_len < p_frag->len);
#if LWIP_6LOWPAN_IPHC
/* Perform 6LowPAN IPv6 header compression according to RFC 6282 */
/* do the header compression (this does NOT copy any non-compressed data) */
err = lowpan6_compress_headers(netif, (u8_t *)p->payload, p->len,
&buffer[ieee_header_len], p_frag->len - ieee_header_len, &lowpan6_header_len,
&hidden_header_len, LWIP_6LOWPAN_CONTEXTS(netif), src, dst);
if (err != ERR_OK) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
pbuf_free(p_frag);
return err;
}
pbuf_remove_header(p, hidden_header_len);
#else /* LWIP_6LOWPAN_IPHC */
/* Send uncompressed IPv6 header with appropriate dispatch byte. */
lowpan6_header_len = 1;
buffer[ieee_header_len] = 0x41; /* IPv6 dispatch */
#endif /* LWIP_6LOWPAN_IPHC */
/* Calculate remaining packet length */
remaining_len = p->tot_len;
if (remaining_len > 0x7FF) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
/* datagram_size must fit into 11 bit */
pbuf_free(p_frag);
return ERR_VAL;
}
/* Fragment, or 1 packet? */
max_data_len = LOWPAN6_MAX_PAYLOAD - ieee_header_len - lowpan6_header_len;
if (remaining_len > max_data_len) {
u16_t data_len;
/* We must move the 6LowPAN header to make room for the FRAG header. */
memmove(&buffer[ieee_header_len + 4], &buffer[ieee_header_len], lowpan6_header_len);
/* Now we need to fragment the packet. FRAG1 header first */
buffer[ieee_header_len] = 0xc0 | (((p->tot_len + hidden_header_len) >> 8) & 0x7);
buffer[ieee_header_len + 1] = (p->tot_len + hidden_header_len) & 0xff;
lowpan6_data.tx_datagram_tag++;
buffer[ieee_header_len + 2] = (lowpan6_data.tx_datagram_tag >> 8) & 0xff;
buffer[ieee_header_len + 3] = lowpan6_data.tx_datagram_tag & 0xff;
/* Fragment follows. */
data_len = (max_data_len - 4) & 0xf8;
frag_len = data_len + lowpan6_header_len;
pbuf_copy_partial(p, buffer + ieee_header_len + lowpan6_header_len + 4, frag_len - lowpan6_header_len, 0);
remaining_len -= frag_len - lowpan6_header_len;
/* datagram offset holds the offset before compression */
datagram_offset = frag_len - lowpan6_header_len + hidden_header_len;
LWIP_ASSERT("datagram offset must be a multiple of 8", (datagram_offset & 7) == 0);
/* Calculate frame length */
p_frag->len = p_frag->tot_len = ieee_header_len + 4 + frag_len + 2; /* add 2 bytes for crc*/
/* 2 bytes CRC */
crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2);
pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2);
/* send the packet */
MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len);
LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p));
err = netif->linkoutput(netif, p_frag);
while ((remaining_len > 0) && (err == ERR_OK)) {
struct ieee_802154_hdr *hdr = (struct ieee_802154_hdr *)buffer;
/* new frame, new seq num for ACK */
hdr->sequence_number = lowpan6_data.tx_frame_seq_num++;
buffer[ieee_header_len] |= 0x20; /* Change FRAG1 to FRAGN */
LWIP_ASSERT("datagram offset must be a multiple of 8", (datagram_offset & 7) == 0);
buffer[ieee_header_len + 4] = (u8_t)(datagram_offset >> 3); /* datagram offset in FRAGN header (datagram_offset is max. 11 bit) */
frag_len = (127 - ieee_header_len - 5 - 2) & 0xf8;
if (frag_len > remaining_len) {
frag_len = remaining_len;
}
pbuf_copy_partial(p, buffer + ieee_header_len + 5, frag_len, p->tot_len - remaining_len);
remaining_len -= frag_len;
datagram_offset += frag_len;
/* Calculate frame length */
p_frag->len = p_frag->tot_len = frag_len + 5 + ieee_header_len + 2;
/* 2 bytes CRC */
crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2);
pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2);
/* send the packet */
MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len);
LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p));
err = netif->linkoutput(netif, p_frag);
}
} else {
/* It fits in one frame. */
frag_len = remaining_len;
/* Copy IPv6 packet */
pbuf_copy_partial(p, buffer + ieee_header_len + lowpan6_header_len, frag_len, 0);
remaining_len = 0;
/* Calculate frame length */
p_frag->len = p_frag->tot_len = frag_len + lowpan6_header_len + ieee_header_len + 2;
LWIP_ASSERT("", p_frag->len <= 127);
/* 2 bytes CRC */
crc = LWIP_6LOWPAN_DO_CALC_CRC(p_frag->payload, p_frag->len - 2);
pbuf_take_at(p_frag, &crc, 2, p_frag->len - 2);
/* send the packet */
MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p_frag->tot_len);
LWIP_DEBUGF(LWIP_LOWPAN6_DEBUG | LWIP_DBG_TRACE, ("lowpan6_send: sending packet %p\n", (void *)p));
err = netif->linkoutput(netif, p_frag);
}
pbuf_free(p_frag);
return err;
}
/**
* @ingroup sixlowpan
* Set context
*/
err_t
lowpan6_set_context(u8_t idx, const ip6_addr_t *context)
{
#if LWIP_6LOWPAN_NUM_CONTEXTS > 0
if (idx >= LWIP_6LOWPAN_NUM_CONTEXTS) {
return ERR_ARG;
}
IP6_ADDR_ZONECHECK(context);
ip6_addr_set(&lowpan6_data.lowpan6_context[idx], context);
return ERR_OK;
#else
LWIP_UNUSED_ARG(idx);
LWIP_UNUSED_ARG(context);
return ERR_ARG;
#endif
}
#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS
/**
* @ingroup sixlowpan
* Set short address
*/
err_t
lowpan6_set_short_addr(u8_t addr_high, u8_t addr_low)
{
short_mac_addr.addr[0] = addr_high;
short_mac_addr.addr[1] = addr_low;
return ERR_OK;
}
#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */
/* Create IEEE 802.15.4 address from netif address */
static err_t
lowpan6_hwaddr_to_addr(struct netif *netif, struct lowpan6_link_addr *addr)
{
addr->addr_len = 8;
if (netif->hwaddr_len == 8) {
LWIP_ERROR("NETIF_MAX_HWADDR_LEN >= 8 required", sizeof(netif->hwaddr) >= 8, return ERR_VAL;);
SMEMCPY(addr->addr, netif->hwaddr, 8);
} else if (netif->hwaddr_len == 6) {
/* Copy from MAC-48 */
SMEMCPY(addr->addr, netif->hwaddr, 3);
addr->addr[3] = addr->addr[4] = 0xff;
SMEMCPY(&addr->addr[5], &netif->hwaddr[3], 3);
} else {
/* Invalid address length, don't know how to convert this */
return ERR_VAL;
}
return ERR_OK;
}
/**
* @ingroup sixlowpan
* Resolve and fill-in IEEE 802.15.4 address header for outgoing IPv6 packet.
*
* Perform Header Compression and fragment if necessary.
*
* @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 err_t
*/
err_t
lowpan6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
{
err_t result;
const u8_t *hwaddr;
struct lowpan6_link_addr src, dest;
#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS
ip6_addr_t ip6_src;
struct ip6_hdr *ip6_hdr;
#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */
#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS
/* Check if we can compress source address (use aligned copy) */
ip6_hdr = (struct ip6_hdr *)q->payload;
ip6_addr_copy_from_packed(ip6_src, ip6_hdr->src);
ip6_addr_assign_zone(&ip6_src, IP6_UNICAST, netif);
if (lowpan6_get_address_mode(&ip6_src, &short_mac_addr) == 3) {
src.addr_len = 2;
src.addr[0] = short_mac_addr.addr[0];
src.addr[1] = short_mac_addr.addr[1];
} else
#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */
{
result = lowpan6_hwaddr_to_addr(netif, &src);
if (result != ERR_OK) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
return result;
}
}
/* multicast destination IP address? */
if (ip6_addr_ismulticast(ip6addr)) {
MIB2_STATS_NETIF_INC(netif, ifoutnucastpkts);
/* We need to send to the broadcast address.*/
return lowpan6_frag(netif, q, &src, &ieee_802154_broadcast);
}
/* We have a unicast destination IP address */
/* @todo anycast? */
#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS
if (src.addr_len == 2) {
/* If source address was compressable to short_mac_addr, and dest has same subnet and
* is also compressable to 2-bytes, assume we can infer dest as a short address too. */
dest.addr_len = 2;
dest.addr[0] = ((u8_t *)q->payload)[38];
dest.addr[1] = ((u8_t *)q->payload)[39];
if ((src.addr_len == 2) && (ip6_addr_netcmp_zoneless(&ip6_hdr->src, &ip6_hdr->dest)) &&
(lowpan6_get_address_mode(ip6addr, &dest) == 3)) {
MIB2_STATS_NETIF_INC(netif, ifoutucastpkts);
return lowpan6_frag(netif, q, &src, &dest);
}
}
#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */
/* Ask ND6 what to do with the packet. */
result = nd6_get_next_hop_addr_or_queue(netif, q, ip6addr, &hwaddr);
if (result != ERR_OK) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
return result;
}
/* If no hardware address is returned, nd6 has queued the packet for later. */
if (hwaddr == NULL) {
return ERR_OK;
}
/* Send out the packet using the returned hardware address. */
dest.addr_len = netif->hwaddr_len;
/* XXX: Inferring the length of the source address from the destination address
* is not correct for IEEE 802.15.4, but currently we don't get this information
* from the neighbor cache */
SMEMCPY(dest.addr, hwaddr, netif->hwaddr_len);
MIB2_STATS_NETIF_INC(netif, ifoutucastpkts);
return lowpan6_frag(netif, q, &src, &dest);
}
/**
* @ingroup sixlowpan
* NETIF input function: don't free the input pbuf when returning != ERR_OK!
*/
err_t
lowpan6_input(struct pbuf *p, struct netif *netif)
{
u8_t *puc, b;
s8_t i;
struct lowpan6_link_addr src, dest;
u16_t datagram_size = 0;
u16_t datagram_offset, datagram_tag;
struct lowpan6_reass_helper *lrh, *lrh_next, *lrh_prev = NULL;
if (p == NULL) {
return ERR_OK;
}
MIB2_STATS_NETIF_ADD(netif, ifinoctets, p->tot_len);
if (p->len != p->tot_len) {
/* for now, this needs a pbuf in one piece */
goto lowpan6_input_discard;
}
if (lowpan6_parse_iee802154_header(p, &src, &dest) != ERR_OK) {
goto lowpan6_input_discard;
}
/* Check dispatch. */
puc = (u8_t *)p->payload;
b = *puc;
if ((b & 0xf8) == 0xc0) {
/* FRAG1 dispatch. add this packet to reassembly list. */
datagram_size = ((u16_t)(puc[0] & 0x07) << 8) | (u16_t)puc[1];
datagram_tag = ((u16_t)puc[2] << 8) | (u16_t)puc[3];
/* check for duplicate */
lrh = lowpan6_data.reass_list;
while (lrh != NULL) {
uint8_t discard = 0;
lrh_next = lrh->next_packet;
if ((lrh->sender_addr.addr_len == src.addr_len) &&
(memcmp(lrh->sender_addr.addr, src.addr, src.addr_len) == 0)) {
/* address match with packet in reassembly. */
if ((datagram_tag == lrh->datagram_tag) && (datagram_size == lrh->datagram_size)) {
/* duplicate fragment. */
goto lowpan6_input_discard;
} else {
/* We are receiving the start of a new datagram. Discard old one (incomplete). */
discard = 1;
}
}
if (discard) {
dequeue_datagram(lrh, lrh_prev);
free_reass_datagram(lrh);
} else {
lrh_prev = lrh;
}
/* Check next datagram in queue. */
lrh = lrh_next;
}
pbuf_remove_header(p, 4); /* hide frag1 dispatch */
lrh = (struct lowpan6_reass_helper *) mem_malloc(sizeof(struct lowpan6_reass_helper));
if (lrh == NULL) {
goto lowpan6_input_discard;
}
lrh->sender_addr.addr_len = src.addr_len;
for (i = 0; i < src.addr_len; i++) {
lrh->sender_addr.addr[i] = src.addr[i];
}
lrh->datagram_size = datagram_size;
lrh->datagram_tag = datagram_tag;
lrh->frags = NULL;
if (*(u8_t *)p->payload == 0x41) {
/* This is a complete IPv6 packet, just skip dispatch byte. */
pbuf_remove_header(p, 1); /* hide dispatch byte. */
lrh->reass = p;
} else if ((*(u8_t *)p->payload & 0xe0 ) == 0x60) {
lrh->reass = lowpan6_decompress(p, datagram_size, LWIP_6LOWPAN_CONTEXTS(netif), &src, &dest);
if (lrh->reass == NULL) {
/* decompression failed */
mem_free(lrh);
goto lowpan6_input_discard;
}
}
/* TODO: handle the case where we already have FRAGN received */
lrh->next_packet = lowpan6_data.reass_list;
lrh->timer = 2;
lowpan6_data.reass_list = lrh;
return ERR_OK;
} else if ((b & 0xf8) == 0xe0) {
/* FRAGN dispatch, find packet being reassembled. */
datagram_size = ((u16_t)(puc[0] & 0x07) << 8) | (u16_t)puc[1];
datagram_tag = ((u16_t)puc[2] << 8) | (u16_t)puc[3];
datagram_offset = (u16_t)puc[4] << 3;
pbuf_remove_header(p, 4); /* hide frag1 dispatch but keep datagram offset for reassembly */
for (lrh = lowpan6_data.reass_list; lrh != NULL; lrh_prev = lrh, lrh = lrh->next_packet) {
if ((lrh->sender_addr.addr_len == src.addr_len) &&
(memcmp(lrh->sender_addr.addr, src.addr, src.addr_len) == 0) &&
(datagram_tag == lrh->datagram_tag) &&
(datagram_size == lrh->datagram_size)) {
break;
}
}
if (lrh == NULL) {
/* rogue fragment */
goto lowpan6_input_discard;
}
/* Insert new pbuf into list of fragments. Each fragment is a pbuf,
this only works for unchained pbufs. */
LWIP_ASSERT("p->next == NULL", p->next == NULL);
if (lrh->reass != NULL) {
/* FRAG1 already received, check this offset against first len */
if (datagram_offset < lrh->reass->len) {
/* fragment overlap, discard old fragments */
dequeue_datagram(lrh, lrh_prev);
free_reass_datagram(lrh);
goto lowpan6_input_discard;
}
}
if (lrh->frags == NULL) {
/* first FRAGN */
lrh->frags = p;
} else {
/* find the correct place to insert */
struct pbuf *q, *last;
u16_t new_frag_len = p->len - 1; /* p->len includes datagram_offset byte */
for (q = lrh->frags, last = NULL; q != NULL; last = q, q = q->next) {
u16_t q_datagram_offset = ((u8_t *)q->payload)[0] << 3;
u16_t q_frag_len = q->len - 1;
if (datagram_offset < q_datagram_offset) {
if (datagram_offset + new_frag_len > q_datagram_offset) {
/* overlap, discard old fragments */
dequeue_datagram(lrh, lrh_prev);
free_reass_datagram(lrh);
goto lowpan6_input_discard;
}
/* insert here */
break;
} else if (datagram_offset == q_datagram_offset) {
if (q_frag_len != new_frag_len) {
/* fragment mismatch, discard old fragments */
dequeue_datagram(lrh, lrh_prev);
free_reass_datagram(lrh);
goto lowpan6_input_discard;
}
/* duplicate, ignore */
pbuf_free(p);
return ERR_OK;
}
}
/* insert fragment */
if (last == NULL) {
lrh->frags = p;
} else {
last->next = p;
p->next = q;
}
}
/* check if all fragments were received */
if (lrh->reass) {
u16_t offset = lrh->reass->len;
struct pbuf *q;
for (q = lrh->frags; q != NULL; q = q->next) {
u16_t q_datagram_offset = ((u8_t *)q->payload)[0] << 3;
if (q_datagram_offset != offset) {
/* not complete, wait for more fragments */
return ERR_OK;
}
offset += q->len - 1;
}
if (offset == datagram_size) {
/* all fragments received, combine pbufs */
u16_t datagram_left = datagram_size - lrh->reass->len;
for (q = lrh->frags; q != NULL; q = q->next) {
/* hide datagram_offset byte now */
pbuf_remove_header(q, 1);
q->tot_len = datagram_left;
datagram_left -= q->len;
}
LWIP_ASSERT("datagram_left == 0", datagram_left == 0);
q = lrh->reass;
q->tot_len = datagram_size;
q->next = lrh->frags;
lrh->frags = NULL;
lrh->reass = NULL;
dequeue_datagram(lrh, lrh_prev);
mem_free(lrh);
/* @todo: distinguish unicast/multicast */
MIB2_STATS_NETIF_INC(netif, ifinucastpkts);
return ip6_input(q, netif);
}
}
/* pbuf enqueued, waiting for more fragments */
return ERR_OK;
} else {
if (b == 0x41) {
/* This is a complete IPv6 packet, just skip dispatch byte. */
pbuf_remove_header(p, 1); /* hide dispatch byte. */
} else if ((b & 0xe0 ) == 0x60) {
/* IPv6 headers are compressed using IPHC. */
p = lowpan6_decompress(p, datagram_size, LWIP_6LOWPAN_CONTEXTS(netif), &src, &dest);
if (p == NULL) {
MIB2_STATS_NETIF_INC(netif, ifindiscards);
return ERR_OK;
}
} else {
goto lowpan6_input_discard;
}
/* @todo: distinguish unicast/multicast */
MIB2_STATS_NETIF_INC(netif, ifinucastpkts);
return ip6_input(p, netif);
}
lowpan6_input_discard:
MIB2_STATS_NETIF_INC(netif, ifindiscards);
pbuf_free(p);
/* always return ERR_OK here to prevent the caller freeing the pbuf */
return ERR_OK;
}
/**
* @ingroup sixlowpan
*/
err_t
lowpan6_if_init(struct netif *netif)
{
netif->name[0] = 'L';
netif->name[1] = '6';
netif->output_ip6 = lowpan6_output;
MIB2_INIT_NETIF(netif, snmp_ifType_other, 0);
/* maximum transfer unit */
netif->mtu = IP6_MIN_MTU_LENGTH;
/* broadcast capability */
netif->flags = NETIF_FLAG_BROADCAST /* | NETIF_FLAG_LOWPAN6 */;
return ERR_OK;
}
/**
* @ingroup sixlowpan
* Set PAN ID
*/
err_t
lowpan6_set_pan_id(u16_t pan_id)
{
lowpan6_data.ieee_802154_pan_id = pan_id;
return ERR_OK;
}
#if !NO_SYS
/**
* @ingroup sixlowpan
* 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
*/
err_t
tcpip_6lowpan_input(struct pbuf *p, struct netif *inp)
{
return tcpip_inpkt(p, inp, lowpan6_input);
}
#endif /* !NO_SYS */
#endif /* LWIP_IPV6 */