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lwip/src/netif/lowpan6.c

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/**
* @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 && LWIP_6LOWPAN
#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_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 ieee_802154_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
/** local PAN ID */
u16_t ieee_802154_pan_id;
u16_t tx_datagram_tag;
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;
static const struct ieee_802154_addr ieee_802154_broadcast = {2, {0xff, 0xff}};
#if LWIP_6LOWPAN_INFER_SHORT_ADDRESS
static struct ieee_802154_addr short_mac_addr = {2, {0, 0}};
#endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */
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;
}
}
/** 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 ieee_802154_addr *src,
const struct ieee_802154_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 ieee_802154_addr *src,
struct ieee_802154_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;
}
#if LWIP_6LOWPAN_IPHC && LWIP_6LOWPAN_NUM_CONTEXTS > 0
static s8_t
lowpan6_context_lookup(const ip6_addr_t *ip6addr)
{
s8_t i;
for (i = 0; i < LWIP_6LOWPAN_NUM_CONTEXTS; i++) {
if (ip6_addr_netcmp(&lowpan6_data.lowpan6_context[i], ip6addr)) {
return i;
}
}
return -1;
}
#endif /* LWIP_6LOWPAN_IPHC && LWIP_6LOWPAN_NUM_CONTEXTS > 0 */
#if LWIP_6LOWPAN_IPHC || LWIP_6LOWPAN_INFER_SHORT_ADDRESS
/* Determine compression mode for unicast address. */
static s8_t
lowpan6_get_address_mode(const ip6_addr_t *ip6addr, const struct ieee_802154_addr *mac_addr)
{
if (mac_addr->addr_len == 2) {
if ((ip6addr->addr[2] == (u32_t)PP_HTONL(0x000000ff)) &&
((ip6addr->addr[3] & PP_HTONL(0xffff0000)) == PP_NTOHL(0xfe000000))) {
if ((ip6addr->addr[3] & PP_HTONL(0x0000ffff)) == lwip_ntohl((mac_addr->addr[0] << 8) | mac_addr->addr[1])) {
return 3;
}
}
} else if (mac_addr->addr_len == 8) {
if ((ip6addr->addr[2] == lwip_ntohl(((mac_addr->addr[0] ^ 2) << 24) | (mac_addr->addr[1] << 16) | mac_addr->addr[2] << 8 | mac_addr->addr[3])) &&
(ip6addr->addr[3] == lwip_ntohl((mac_addr->addr[4] << 24) | (mac_addr->addr[5] << 16) | mac_addr->addr[6] << 8 | mac_addr->addr[7]))) {
return 3;
}
}
if ((ip6addr->addr[2] == PP_HTONL(0x000000ffUL)) &&
((ip6addr->addr[3] & PP_HTONL(0xffff0000)) == PP_NTOHL(0xfe000000UL))) {
return 2;
}
return 1;
}
#endif /* LWIP_6LOWPAN_IPHC || LWIP_6LOWPAN_INFER_SHORT_ADDRESS */
#if LWIP_6LOWPAN_IPHC
/* Determine compression mode for multicast address. */
static s8_t
lowpan6_get_address_mode_mc(const ip6_addr_t *ip6addr)
{
if ((ip6addr->addr[0] == PP_HTONL(0xff020000)) &&
(ip6addr->addr[1] == 0) &&
(ip6addr->addr[2] == 0) &&
((ip6addr->addr[3] & PP_HTONL(0xffffff00)) == 0)) {
return 3;
} else if (((ip6addr->addr[0] & PP_HTONL(0xff00ffff)) == PP_HTONL(0xff000000)) &&
(ip6addr->addr[1] == 0)) {
if ((ip6addr->addr[2] == 0) &&
((ip6addr->addr[3] & PP_HTONL(0xff000000)) == 0)) {
return 2;
} else if ((ip6addr->addr[2] & PP_HTONL(0xffffff00)) == 0) {
return 1;
}
}
return 0;
}
#endif /* LWIP_6LOWPAN_IPHC */
/*
* 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 ieee_802154_addr *src, const struct ieee_802154_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 = 0;
s8_t i;
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);
#if LWIP_6LOWPAN_IPHC
/* Perform 6LowPAN IPv6 header compression according to RFC 6282 */
{
struct ip6_hdr *ip6hdr;
/* Point to ip6 header and align copies of src/dest addresses. */
ip6hdr = (struct ip6_hdr *)p->payload;
ip_addr_copy_from_ip6_packed(ip_data.current_iphdr_dest, ip6hdr->dest);
ip6_addr_assign_zone(ip_2_ip6(&ip_data.current_iphdr_dest), IP6_UNKNOWN, netif);
ip_addr_copy_from_ip6_packed(ip_data.current_iphdr_src, ip6hdr->src);
ip6_addr_assign_zone(ip_2_ip6(&ip_data.current_iphdr_src), IP6_UNKNOWN, netif);
/* Basic length of 6LowPAN header, set dispatch and clear fields. */
lowpan6_header_len = 2;
buffer[ieee_header_len] = 0x60;
buffer[ieee_header_len + 1] = 0;
/* Determine whether there will be a Context Identifier Extension byte or not.
* If so, set it already. */
#if LWIP_6LOWPAN_NUM_CONTEXTS > 0
buffer[ieee_header_len + 2] = 0;
i = lowpan6_context_lookup(ip_2_ip6(&ip_data.current_iphdr_src));
if (i >= 0) {
/* Stateful source address compression. */
buffer[ieee_header_len + 1] |= 0x40;
buffer[ieee_header_len + 2] |= (i & 0x0f) << 4;
}
i = lowpan6_context_lookup(ip_2_ip6(&ip_data.current_iphdr_dest));
if (i >= 0) {
/* Stateful destination address compression. */
buffer[ieee_header_len + 1] |= 0x04;
buffer[ieee_header_len + 2] |= i & 0x0f;
}
if (buffer[ieee_header_len + 2] != 0x00) {
/* Context identifier extension byte is appended. */
buffer[ieee_header_len + 1] |= 0x80;
lowpan6_header_len++;
}
#endif /* LWIP_6LOWPAN_NUM_CONTEXTS > 0 */
/* Determine TF field: Traffic Class, Flow Label */
if (IP6H_FL(ip6hdr) == 0) {
/* Flow label is elided. */
buffer[ieee_header_len] |= 0x10;
if (IP6H_TC(ip6hdr) == 0) {
/* Traffic class (ECN+DSCP) elided too. */
buffer[ieee_header_len] |= 0x08;
} else {
/* Traffic class (ECN+DSCP) appended. */
buffer[ieee_header_len + lowpan6_header_len++] = IP6H_TC(ip6hdr);
}
} else {
if (((IP6H_TC(ip6hdr) & 0x3f) == 0)) {
/* DSCP portion of Traffic Class is elided, ECN and FL are appended (3 bytes) */
buffer[ieee_header_len] |= 0x08;
buffer[ieee_header_len + lowpan6_header_len] = IP6H_TC(ip6hdr) & 0xc0;
buffer[ieee_header_len + lowpan6_header_len++] |= (IP6H_FL(ip6hdr) >> 16) & 0x0f;
buffer[ieee_header_len + lowpan6_header_len++] = (IP6H_FL(ip6hdr) >> 8) & 0xff;
buffer[ieee_header_len + lowpan6_header_len++] = IP6H_FL(ip6hdr) & 0xff;
} else {
/* Traffic class and flow label are appended (4 bytes) */
buffer[ieee_header_len + lowpan6_header_len++] = IP6H_TC(ip6hdr);
buffer[ieee_header_len + lowpan6_header_len++] = (IP6H_FL(ip6hdr) >> 16) & 0x0f;
buffer[ieee_header_len + lowpan6_header_len++] = (IP6H_FL(ip6hdr) >> 8) & 0xff;
buffer[ieee_header_len + lowpan6_header_len++] = IP6H_FL(ip6hdr) & 0xff;
}
}
/* Compress NH?
* Only if UDP for now. @todo support other NH compression. */
if (IP6H_NEXTH(ip6hdr) == IP6_NEXTH_UDP) {
buffer[ieee_header_len] |= 0x04;
} else {
/* append nexth. */
buffer[ieee_header_len + lowpan6_header_len++] = IP6H_NEXTH(ip6hdr);
}
/* Compress hop limit? */
if (IP6H_HOPLIM(ip6hdr) == 255) {
buffer[ieee_header_len] |= 0x03;
} else if (IP6H_HOPLIM(ip6hdr) == 64) {
buffer[ieee_header_len] |= 0x02;
} else if (IP6H_HOPLIM(ip6hdr) == 1) {
buffer[ieee_header_len] |= 0x01;
} else {
/* append hop limit */
buffer[ieee_header_len + lowpan6_header_len++] = IP6H_HOPLIM(ip6hdr);
}
/* Compress source address */
if (((buffer[ieee_header_len + 1] & 0x40) != 0) ||
(ip6_addr_islinklocal(ip_2_ip6(&ip_data.current_iphdr_src)))) {
/* Context-based or link-local source address compression. */
i = lowpan6_get_address_mode(ip_2_ip6(&ip_data.current_iphdr_src), src);
buffer[ieee_header_len + 1] |= (i & 0x03) << 4;
if (i == 1) {
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 16, 8);
lowpan6_header_len += 8;
} else if (i == 2) {
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 22, 2);
lowpan6_header_len += 2;
}
} else if (ip6_addr_isany(ip_2_ip6(&ip_data.current_iphdr_src))) {
/* Special case: mark SAC and leave SAM=0 */
buffer[ieee_header_len + 1] |= 0x40;
} else {
/* Append full address. */
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 8, 16);
lowpan6_header_len += 16;
}
/* Compress destination address */
if (ip6_addr_ismulticast(ip_2_ip6(&ip_data.current_iphdr_dest))) {
/* @todo support stateful multicast address compression */
buffer[ieee_header_len + 1] |= 0x08;
i = lowpan6_get_address_mode_mc(ip_2_ip6(&ip_data.current_iphdr_dest));
buffer[ieee_header_len + 1] |= i & 0x03;
if (i == 0) {
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 24, 16);
lowpan6_header_len += 16;
} else if (i == 1) {
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[25];
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 35, 5);
lowpan6_header_len += 5;
} else if (i == 2) {
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[25];
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 37, 3);
lowpan6_header_len += 3;
} else if (i == 3) {
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[39];
}
} else if (((buffer[ieee_header_len + 1] & 0x04) != 0) ||
(ip6_addr_islinklocal(ip_2_ip6(&ip_data.current_iphdr_dest)))) {
/* Context-based or link-local destination address compression. */
i = lowpan6_get_address_mode(ip_2_ip6(&ip_data.current_iphdr_dest), dst);
buffer[ieee_header_len + 1] |= i & 0x03;
if (i == 1) {
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 32, 8);
lowpan6_header_len += 8;
} else if (i == 2) {
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 38, 2);
lowpan6_header_len += 2;
}
} else {
/* Append full address. */
MEMCPY(buffer + ieee_header_len + lowpan6_header_len, (u8_t *)p->payload + 24, 16);
lowpan6_header_len += 16;
}
/* Move to payload. */
pbuf_remove_header(p, IP6_HLEN);
hidden_header_len += IP6_HLEN;
#if LWIP_UDP
/* Compress UDP header? */
if (IP6H_NEXTH(ip6hdr) == IP6_NEXTH_UDP) {
/* @todo support optional checksum compression */
buffer[ieee_header_len + lowpan6_header_len] = 0xf0;
/* determine port compression mode. */
if ((((u8_t *)p->payload)[0] == 0xf0) && ((((u8_t *)p->payload)[1] & 0xf0) == 0xb0) &&
(((u8_t *)p->payload)[2] == 0xf0) && ((((u8_t *)p->payload)[3] & 0xf0) == 0xb0)) {
/* Compress source and dest ports. */
buffer[ieee_header_len + lowpan6_header_len++] |= 0x03;
buffer[ieee_header_len + lowpan6_header_len++] = ((((u8_t *)p->payload)[1] & 0x0f) << 4) | (((u8_t *)p->payload)[3] & 0x0f);
} else if (((u8_t *)p->payload)[0] == 0xf0) {
/* Compress source port. */
buffer[ieee_header_len + lowpan6_header_len++] |= 0x02;
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[1];
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[2];
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[3];
} else if (((u8_t *)p->payload)[2] == 0xf0) {
/* Compress dest port. */
buffer[ieee_header_len + lowpan6_header_len++] |= 0x01;
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[0];
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[1];
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[3];
} else {
/* append full ports. */
lowpan6_header_len++;
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[0];
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[1];
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[2];
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[3];
}
/* elide length and copy checksum */
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[6];
buffer[ieee_header_len + lowpan6_header_len++] = ((u8_t *)p->payload)[7];
pbuf_remove_header(p, UDP_HLEN);
hidden_header_len += UDP_HLEN;
}
#endif /* LWIP_UDP */
}
#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 = (127 - ieee_header_len - 4 - 2) & 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(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(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(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 ieee_802154_addr *addr)
{
addr->addr_len = 8;
if (netif->hwaddr_len == 8) {
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 ieee_802154_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. */
result = lowpan6_hwaddr_to_addr(netif, &dest);
if (result != ERR_OK) {
MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
return result;
}
MIB2_STATS_NETIF_INC(netif, ifoutucastpkts);
return lowpan6_frag(netif, q, &src, &dest);
}
/** Decompress IPv6 and UDP headers compressed according to RFC 6282
*
* @param lowpan6_buffer compressed headers, first byte is the dispatch byte
* @param lowpan6_bufsize size of lowpan6_buffer (may include data after headers)
* @param decomp_buffer buffer where the decompressed headers are stored
* @param decomp_bufsize size of decomp_buffer
* @param hdr_size_comp returns the size of the compressed headers (skip to get to data)
* @param hdr_size_decomp returns the size of the decompressed headers (IPv6 + UDP)
* @param datagram_size datagram size from fragments or 0 if unfragmented
* @param compressed_size compressed datagram size (for unfragmented rx)
* @param src source address of the outer layer, used for address compression
* @param dest destination address of the outer layer, used for address compression
* @return ERR_OK if decompression succeeded, an error otherwise
*/
static err_t
lowpan6_decompress_hdr(u8_t *lowpan6_buffer, size_t lowpan6_bufsize,
u8_t *decomp_buffer, size_t decomp_bufsize,
u16_t *hdr_size_comp, u16_t *hdr_size_decomp,
u16_t datagram_size, u16_t compressed_size,
struct ieee_802154_addr *src, struct ieee_802154_addr *dest)
{
u16_t lowpan6_offset;
struct ip6_hdr *ip6hdr;
s8_t i;
u16_t ip6_offset = IP6_HLEN;
LWIP_ASSERT("lowpan6_buffer != NULL", lowpan6_buffer != NULL);
LWIP_ASSERT("decomp_buffer != NULL", decomp_buffer != NULL);
LWIP_ASSERT("src != NULL", src != NULL);
LWIP_ASSERT("dest != NULL", dest != NULL);
ip6hdr = (struct ip6_hdr *)decomp_buffer;
if (decomp_bufsize < IP6_HLEN) {
return ERR_MEM;
}
lowpan6_offset = 2;
if (lowpan6_buffer[1] & 0x80) {
lowpan6_offset++;
}
/* Set IPv6 version, traffic class and flow label. */
if ((lowpan6_buffer[0] & 0x18) == 0x00) {
IP6H_VTCFL_SET(ip6hdr, 6, lowpan6_buffer[lowpan6_offset], ((lowpan6_buffer[lowpan6_offset + 1] & 0x0f) << 16) | (lowpan6_buffer[lowpan6_offset + 2] << 8) | lowpan6_buffer[lowpan6_offset + 3]);
lowpan6_offset += 4;
} else if ((lowpan6_buffer[0] & 0x18) == 0x08) {
IP6H_VTCFL_SET(ip6hdr, 6, lowpan6_buffer[lowpan6_offset] & 0xc0, ((lowpan6_buffer[lowpan6_offset] & 0x0f) << 16) | (lowpan6_buffer[lowpan6_offset + 1] << 8) | lowpan6_buffer[lowpan6_offset + 2]);
lowpan6_offset += 3;
} else if ((lowpan6_buffer[0] & 0x18) == 0x10) {
IP6H_VTCFL_SET(ip6hdr, 6, lowpan6_buffer[lowpan6_offset], 0);
lowpan6_offset += 1;
} else if ((lowpan6_buffer[0] & 0x18) == 0x18) {
IP6H_VTCFL_SET(ip6hdr, 6, 0, 0);
}
/* Set Next Header */
if ((lowpan6_buffer[0] & 0x04) == 0x00) {
IP6H_NEXTH_SET(ip6hdr, lowpan6_buffer[lowpan6_offset++]);
} else {
/* We should fill this later with NHC decoding */
IP6H_NEXTH_SET(ip6hdr, 0);
}
/* Set Hop Limit */
if ((lowpan6_buffer[0] & 0x03) == 0x00) {
IP6H_HOPLIM_SET(ip6hdr, lowpan6_buffer[lowpan6_offset++]);
} else if ((lowpan6_buffer[0] & 0x03) == 0x01) {
IP6H_HOPLIM_SET(ip6hdr, 1);
} else if ((lowpan6_buffer[0] & 0x03) == 0x02) {
IP6H_HOPLIM_SET(ip6hdr, 64);
} else if ((lowpan6_buffer[0] & 0x03) == 0x03) {
IP6H_HOPLIM_SET(ip6hdr, 255);
}
/* Source address decoding. */
if ((lowpan6_buffer[1] & 0x40) == 0x00) {
/* Stateless compression */
if ((lowpan6_buffer[1] & 0x30) == 0x00) {
/* copy full address */
MEMCPY(&ip6hdr->src.addr[0], lowpan6_buffer + lowpan6_offset, 16);
lowpan6_offset += 16;
} else if ((lowpan6_buffer[1] & 0x30) == 0x10) {
ip6hdr->src.addr[0] = PP_HTONL(0xfe800000UL);
ip6hdr->src.addr[1] = 0;
MEMCPY(&ip6hdr->src.addr[2], lowpan6_buffer + lowpan6_offset, 8);
lowpan6_offset += 8;
} else if ((lowpan6_buffer[1] & 0x30) == 0x20) {
ip6hdr->src.addr[0] = PP_HTONL(0xfe800000UL);
ip6hdr->src.addr[1] = 0;
ip6hdr->src.addr[2] = PP_HTONL(0x000000ffUL);
ip6hdr->src.addr[3] = lwip_htonl(0xfe000000UL | (lowpan6_buffer[lowpan6_offset] << 8) |
lowpan6_buffer[lowpan6_offset + 1]);
lowpan6_offset += 2;
} else if ((lowpan6_buffer[1] & 0x30) == 0x30) {
ip6hdr->src.addr[0] = PP_HTONL(0xfe800000UL);
ip6hdr->src.addr[1] = 0;
if (src->addr_len == 2) {
ip6hdr->src.addr[2] = PP_HTONL(0x000000ffUL);
ip6hdr->src.addr[3] = lwip_htonl(0xfe000000UL | (src->addr[0] << 8) | src->addr[1]);
} else {
ip6hdr->src.addr[2] = lwip_htonl(((src->addr[0] ^ 2) << 24) | (src->addr[1] << 16) |
(src->addr[2] << 8) | src->addr[3]);
ip6hdr->src.addr[3] = lwip_htonl((src->addr[4] << 24) | (src->addr[5] << 16) |
(src->addr[6] << 8) | src->addr[7]);
}
}
} else {
/* Stateful compression */
if ((lowpan6_buffer[1] & 0x30) == 0x00) {
/* ANY address */
ip6hdr->src.addr[0] = 0;
ip6hdr->src.addr[1] = 0;
ip6hdr->src.addr[2] = 0;
ip6hdr->src.addr[3] = 0;
} else {
/* Set prefix from context info */
if (lowpan6_buffer[1] & 0x80) {
i = (lowpan6_buffer[2] >> 4) & 0x0f;
} else {
i = 0;
}
if (i >= LWIP_6LOWPAN_NUM_CONTEXTS) {
/* Error */
return ERR_VAL;
}
#if LWIP_6LOWPAN_NUM_CONTEXTS > 0
ip6hdr->src.addr[0] = lowpan6_data.lowpan6_context[i].addr[0];
ip6hdr->src.addr[1] = lowpan6_data.lowpan6_context[i].addr[1];
#endif
}
if ((lowpan6_buffer[1] & 0x30) == 0x10) {
MEMCPY(&ip6hdr->src.addr[2], lowpan6_buffer + lowpan6_offset, 8);
lowpan6_offset += 8;
} else if ((lowpan6_buffer[1] & 0x30) == 0x20) {
ip6hdr->src.addr[2] = PP_HTONL(0x000000ffUL);
ip6hdr->src.addr[3] = lwip_htonl(0xfe000000UL | (lowpan6_buffer[lowpan6_offset] << 8) | lowpan6_buffer[lowpan6_offset + 1]);
lowpan6_offset += 2;
} else if ((lowpan6_buffer[1] & 0x30) == 0x30) {
if (src->addr_len == 2) {
ip6hdr->src.addr[2] = PP_HTONL(0x000000ffUL);
ip6hdr->src.addr[3] = lwip_htonl(0xfe000000UL | (src->addr[0] << 8) | src->addr[1]);
} else {
ip6hdr->src.addr[2] = lwip_htonl(((src->addr[0] ^ 2) << 24) | (src->addr[1] << 16) | (src->addr[2] << 8) | src->addr[3]);
ip6hdr->src.addr[3] = lwip_htonl((src->addr[4] << 24) | (src->addr[5] << 16) | (src->addr[6] << 8) | src->addr[7]);
}
}
}
/* Destination address decoding. */
if (lowpan6_buffer[1] & 0x08) {
/* Multicast destination */
if (lowpan6_buffer[1] & 0x04) {
/* @todo support stateful multicast addressing */
return ERR_VAL;
}
if ((lowpan6_buffer[1] & 0x03) == 0x00) {
/* copy full address */
MEMCPY(&ip6hdr->dest.addr[0], lowpan6_buffer + lowpan6_offset, 16);
lowpan6_offset += 16;
} else if ((lowpan6_buffer[1] & 0x03) == 0x01) {
ip6hdr->dest.addr[0] = lwip_htonl(0xff000000UL | (lowpan6_buffer[lowpan6_offset++] << 16));
ip6hdr->dest.addr[1] = 0;
ip6hdr->dest.addr[2] = lwip_htonl(lowpan6_buffer[lowpan6_offset++]);
ip6hdr->dest.addr[3] = lwip_htonl((lowpan6_buffer[lowpan6_offset] << 24) | (lowpan6_buffer[lowpan6_offset + 1] << 16) | (lowpan6_buffer[lowpan6_offset + 2] << 8) | lowpan6_buffer[lowpan6_offset + 3]);
lowpan6_offset += 4;
} else if ((lowpan6_buffer[1] & 0x03) == 0x02) {
ip6hdr->dest.addr[0] = lwip_htonl(0xff000000UL | (lowpan6_buffer[lowpan6_offset++] << 16));
ip6hdr->dest.addr[1] = 0;
ip6hdr->dest.addr[2] = 0;
ip6hdr->dest.addr[3] = lwip_htonl((lowpan6_buffer[lowpan6_offset] << 16) | (lowpan6_buffer[lowpan6_offset + 1] << 8) | lowpan6_buffer[lowpan6_offset + 2]);
lowpan6_offset += 3;
} else if ((lowpan6_buffer[1] & 0x03) == 0x03) {
ip6hdr->dest.addr[0] = PP_HTONL(0xff020000UL);
ip6hdr->dest.addr[1] = 0;
ip6hdr->dest.addr[2] = 0;
ip6hdr->dest.addr[3] = lwip_htonl(lowpan6_buffer[lowpan6_offset++]);
}
} else {
if (lowpan6_buffer[1] & 0x04) {
/* Stateful destination compression */
/* Set prefix from context info */
if (lowpan6_buffer[1] & 0x80) {
i = lowpan6_buffer[2] & 0x0f;
} else {
i = 0;
}
if (i >= LWIP_6LOWPAN_NUM_CONTEXTS) {
/* Error */
return ERR_VAL;
}
#if LWIP_6LOWPAN_NUM_CONTEXTS > 0
ip6hdr->dest.addr[0] = lowpan6_data.lowpan6_context[i].addr[0];
ip6hdr->dest.addr[1] = lowpan6_data.lowpan6_context[i].addr[1];
#endif
} else {
/* Link local address compression */
ip6hdr->dest.addr[0] = PP_HTONL(0xfe800000UL);
ip6hdr->dest.addr[1] = 0;
}
if ((lowpan6_buffer[1] & 0x03) == 0x00) {
/* copy full address */
MEMCPY(&ip6hdr->dest.addr[0], lowpan6_buffer + lowpan6_offset, 16);
lowpan6_offset += 16;
} else if ((lowpan6_buffer[1] & 0x03) == 0x01) {
MEMCPY(&ip6hdr->dest.addr[2], lowpan6_buffer + lowpan6_offset, 8);
lowpan6_offset += 8;
} else if ((lowpan6_buffer[1] & 0x03) == 0x02) {
ip6hdr->dest.addr[2] = PP_HTONL(0x000000ffUL);
ip6hdr->dest.addr[3] = lwip_htonl(0xfe000000UL | (lowpan6_buffer[lowpan6_offset] << 8) | lowpan6_buffer[lowpan6_offset + 1]);
lowpan6_offset += 2;
} else if ((lowpan6_buffer[1] & 0x03) == 0x03) {
if (dest->addr_len == 2) {
ip6hdr->dest.addr[2] = PP_HTONL(0x000000ffUL);
ip6hdr->dest.addr[3] = lwip_htonl(0xfe000000UL | (dest->addr[0] << 8) | dest->addr[1]);
} else {
ip6hdr->dest.addr[2] = lwip_htonl(((dest->addr[0] ^ 2) << 24) | (dest->addr[1] << 16) | dest->addr[2] << 8 | dest->addr[3]);
ip6hdr->dest.addr[3] = lwip_htonl((dest->addr[4] << 24) | (dest->addr[5] << 16) | dest->addr[6] << 8 | dest->addr[7]);
}
}
}
/* Next Header Compression (NHC) decoding? */
if (lowpan6_buffer[0] & 0x04) {
#if LWIP_UDP
if ((lowpan6_buffer[lowpan6_offset] & 0xf8) == 0xf0) {
struct udp_hdr *udphdr;
/* UDP compression */
IP6H_NEXTH_SET(ip6hdr, IP6_NEXTH_UDP);
udphdr = (struct udp_hdr *)((u8_t *)decomp_buffer + ip6_offset);
if (decomp_bufsize < IP6_HLEN + UDP_HLEN) {
return ERR_MEM;
}
if (lowpan6_buffer[lowpan6_offset] & 0x04) {
/* @todo support checksum decompress */
return ERR_VAL;
}
/* Decompress ports */
i = lowpan6_buffer[lowpan6_offset++] & 0x03;
if (i == 0) {
udphdr->src = lwip_htons(lowpan6_buffer[lowpan6_offset] << 8 | lowpan6_buffer[lowpan6_offset + 1]);
udphdr->dest = lwip_htons(lowpan6_buffer[lowpan6_offset + 2] << 8 | lowpan6_buffer[lowpan6_offset + 3]);
lowpan6_offset += 4;
} else if (i == 0x01) {
udphdr->src = lwip_htons(lowpan6_buffer[lowpan6_offset] << 8 | lowpan6_buffer[lowpan6_offset + 1]);
udphdr->dest = lwip_htons(0xf000 | lowpan6_buffer[lowpan6_offset + 2]);
lowpan6_offset += 3;
} else if (i == 0x02) {
udphdr->src = lwip_htons(0xf000 | lowpan6_buffer[lowpan6_offset]);
udphdr->dest = lwip_htons(lowpan6_buffer[lowpan6_offset + 1] << 8 | lowpan6_buffer[lowpan6_offset + 2]);
lowpan6_offset += 3;
} else if (i == 0x03) {
udphdr->src = lwip_htons(0xf0b0 | ((lowpan6_buffer[lowpan6_offset] >> 4) & 0x0f));
udphdr->dest = lwip_htons(0xf0b0 | (lowpan6_buffer[lowpan6_offset] & 0x0f));
lowpan6_offset += 1;
}
udphdr->chksum = lwip_htons(lowpan6_buffer[lowpan6_offset] << 8 | lowpan6_buffer[lowpan6_offset + 1]);
lowpan6_offset += 2;
ip6_offset += UDP_HLEN;
if (datagram_size == 0) {
datagram_size = compressed_size - lowpan6_offset + ip6_offset;
}
udphdr->len = lwip_htons(datagram_size - IP6_HLEN);
} else
#endif /* LWIP_UDP */
{
/* @todo support NHC other than UDP */
return ERR_VAL;
}
}
if (datagram_size == 0) {
datagram_size = compressed_size - lowpan6_offset + ip6_offset;
}
/* Infer IPv6 payload length for header */
IP6H_PLEN_SET(ip6hdr, datagram_size - IP6_HLEN);
if (lowpan6_offset > lowpan6_bufsize) {
/* input buffer overflow */
return ERR_VAL;
}
if (hdr_size_comp) {
*hdr_size_comp = lowpan6_offset;
}
if (hdr_size_decomp) {
*hdr_size_decomp = ip6_offset;
}
return ERR_OK;
}
static struct pbuf *
lowpan6_decompress(struct pbuf *p, u16_t datagram_size, struct ieee_802154_addr *src, struct ieee_802154_addr *dest)
{
struct pbuf *q;
u16_t lowpan6_offset, ip6_offset;
err_t err;
#if LWIP_UDP
#define UDP_HLEN_ALLOC UDP_HLEN
#else
#define UDP_HLEN_ALLOC 0
#endif
/* Allocate a buffer for decompression. This buffer will be too big and will be
trimmed once the final size is known. */
q = pbuf_alloc(PBUF_IP, p->len + IP6_HLEN + UDP_HLEN_ALLOC, PBUF_POOL);
if (q == NULL) {
pbuf_free(p);
return NULL;
}
if (q->len < IP6_HLEN + UDP_HLEN_ALLOC) {
/* The headers need to fit into the first pbuf */
pbuf_free(p);
pbuf_free(q);
return NULL;
}
/* Decompress the IPv6 (and possibly UDP) header(s) into the new pbuf */
err = lowpan6_decompress_hdr((u8_t *)p->payload, p->len, (u8_t *)q->payload, q->len,
&lowpan6_offset, &ip6_offset, datagram_size, p->tot_len, src, dest);
if (err != ERR_OK) {
pbuf_free(p);
pbuf_free(q);
return NULL;
}
/* Now we copy leftover contents from p to q, so we have all L2 and L3 headers
(and L4?) in a single pbuf: */
/* Hide the compressed headers in p */
pbuf_remove_header(p, lowpan6_offset);
/* Temporarily hide the headers in q... */
pbuf_remove_header(q, ip6_offset);
/* ... copy the rest of p into q... */
pbuf_copy(q, p);
/* ... and reveal the headers again... */
pbuf_add_header_force(q, ip6_offset);
/* ... trim the pbuf to its correct size... */
pbuf_realloc(q, ip6_offset + p->len);
/* ... and cat possibly remaining (data-only) pbufs */
if (p->next != NULL) {
pbuf_cat(q, p->next);
}
/* the original (first) pbuf can now be freed */
p->next = NULL;
pbuf_free(p);
/* all done */
return q;
}
/**
* @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 ieee_802154_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, &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, &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 = 1280;
/* 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 && LWIP_6LOWPAN */
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