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nes-proj/os/net/ipv6/sicslowpan.c

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/*
* Copyright (c) 2008, Swedish Institute of Computer Science.
* 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. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
*/
/**
* \file
* 6lowpan implementation (RFC4944 and draft-ietf-6lowpan-hc-06)
*
* \author Adam Dunkels <adam@sics.se>
* \author Nicolas Tsiftes <nvt@sics.se>
* \author Niclas Finne <nfi@sics.se>
* \author Mathilde Durvy <mdurvy@cisco.com>
* \author Julien Abeille <jabeille@cisco.com>
* \author Joakim Eriksson <joakime@sics.se>
* \author Joel Hoglund <joel@sics.se>
*/
/**
* \addtogroup sicslowpan
* \ingroup uip
* @{
*/
/**
* FOR HC-06 COMPLIANCE TODO:
* -Add compression options to UDP, currently only supports
* both ports compressed or both ports elided
*
* -Verify TC/FL compression works
*
* -Add stateless multicast option
*/
#include <string.h>
#include "contiki.h"
#include "dev/watchdog.h"
#include "net/link-stats.h"
#include "net/ipv6/uipopt.h"
#include "net/ipv6/tcpip.h"
#include "net/ipv6/uip.h"
#include "net/ipv6/uip-ds6.h"
#include "net/ipv6/uipbuf.h"
#include "net/ipv6/sicslowpan.h"
#include "net/netstack.h"
#include "net/packetbuf.h"
#include "net/queuebuf.h"
#include "net/routing/routing.h"
/* Log configuration */
#include "sys/log.h"
#define LOG_MODULE "6LoWPAN"
#define LOG_LEVEL LOG_LEVEL_6LOWPAN
#define GET16(ptr,index) (((uint16_t)((ptr)[index] << 8)) | ((ptr)[(index) + 1]))
#define SET16(ptr,index,value) do { \
(ptr)[index] = ((value) >> 8) & 0xff; \
(ptr)[index + 1] = (value) & 0xff; \
} while(0)
/** \name Pointers in the packetbuf buffer
* @{
*/
#define PACKETBUF_FRAG_PTR (packetbuf_ptr)
#define PACKETBUF_FRAG_DISPATCH_SIZE 0 /* 16 bit */
#define PACKETBUF_FRAG_TAG 2 /* 16 bit */
#define PACKETBUF_FRAG_OFFSET 4 /* 8 bit */
/* define the buffer as a byte array */
#define PACKETBUF_IPHC_BUF ((uint8_t *)(packetbuf_ptr + packetbuf_hdr_len))
#define PACKETBUF_PAYLOAD_END ((uint8_t *)(packetbuf_ptr + mac_max_payload))
#define PACKETBUF_6LO_PTR (packetbuf_ptr + packetbuf_hdr_len)
#define PACKETBUF_6LO_DISPATCH 0 /* 8 bit */
#define PACKETBUF_6LO_ENCODING 1 /* 8 bit */
#define PACKETBUF_6LO_TTL 2 /* 8 bit */
#define PACKETBUF_6LO_HC_UDP_PTR (packetbuf_ptr + packetbuf_hdr_len)
#define PACKETBUF_6LO_HC_UDP_DISPATCH 0 /* 8 bit */
#define PACKETBUF_6LO_HC_UDP_HC1_ENCODING 1 /* 8 bit */
#define PACKETBUF_6LO_HC_UDP_UDP_ENCODING 2 /* 8 bit */
#define PACKETBUF_6LO_HC_UDP_TTL 3 /* 8 bit */
#define PACKETBUF_6LO_HC_UDP_PORTS 4 /* 8 bit */
#define PACKETBUF_6LO_HC_UDP_CHKSUM 5 /* 16 bit */
/** \name Pointers in the sicslowpan and uip buffer
* @{
*/
/* NOTE: In the multiple-reassembly context there is only room for the header / first fragment */
#define SICSLOWPAN_IP_BUF(buf) ((struct uip_ip_hdr *)buf)
#define SICSLOWPAN_UDP_BUF(buf) ((struct uip_udp_hdr *)&buf[UIP_IPH_LEN])
#define SICSLOWPAN_IPPAYLOAD_BUF(buf) (&buf[UIP_IPH_LEN])
#define UIP_IPPAYLOAD_BUF_POS(pos) (&uip_buf[UIP_IPH_LEN + (pos)])
#define UIP_UDP_BUF_POS(pos) ((struct uip_udp_hdr *)UIP_IPPAYLOAD_BUF_POS(pos))
/** @} */
/* set this to zero if not compressing EXT_HDR - for backwards compatibility */
#ifdef SICSLOWPAN_CONF_COMPRESS_EXT_HDR
#define COMPRESS_EXT_HDR SICSLOWPAN_CONF_COMPRESS_EXT_HDR
#else
/* Compressing on by default - turn off to be compatible with older versions */
#define COMPRESS_EXT_HDR 1
#endif
#if COMPRESS_EXT_HDR
#define IS_COMPRESSABLE_PROTO(x) (x == UIP_PROTO_UDP \
|| x == UIP_PROTO_HBHO \
|| x == UIP_PROTO_DESTO \
|| x == UIP_PROTO_ROUTING \
|| x == UIP_PROTO_FRAG)
#else
#define IS_COMPRESSABLE_PROTO(x) (x == UIP_PROTO_UDP)
#endif /* COMPRESS_EXT_HDR */
/** \name General variables
* @{
*/
/**
* A pointer to the packetbuf buffer.
* We initialize it to the beginning of the packetbuf buffer, then
* access different fields by updating the offset packetbuf_hdr_len.
*/
static uint8_t *packetbuf_ptr;
/**
* packetbuf_hdr_len is the total length of (the processed) 6lowpan headers
* (fragment headers, IPV6 or HC1, HC2, and HC1 and HC2 non compressed
* fields).
*/
static uint8_t packetbuf_hdr_len;
/**
* The length of the payload in the Packetbuf buffer.
* The payload is what comes after the compressed or uncompressed
* headers (can be the IP payload if the IP header only is compressed
* or the UDP payload if the UDP header is also compressed)
*/
static int packetbuf_payload_len;
/**
* uncomp_hdr_len is the length of the headers before compression (if HC2
* is used this includes the UDP header in addition to the IP header).
*/
static uint8_t uncomp_hdr_len;
/**
* mac_max_payload is the maimum payload space on the MAC frame.
*/
static int mac_max_payload;
/**
* The current page (RFC 4944)
*/
static uint8_t curr_page;
/**
* the result of the last transmitted fragment
*/
static int last_tx_status;
/** @} */
static int last_rssi;
/* ----------------------------------------------------------------- */
/* Support for reassembling multiple packets */
/* ----------------------------------------------------------------- */
#if SICSLOWPAN_CONF_FRAG
static uint16_t my_tag;
/** The total length of the IPv6 packet in the sicslowpan_buf. */
/* This needs to be defined in NBR / Nodes depending on available RAM */
/* and expected reassembly requirements */
#ifdef SICSLOWPAN_CONF_FRAGMENT_BUFFERS
#define SICSLOWPAN_FRAGMENT_BUFFERS SICSLOWPAN_CONF_FRAGMENT_BUFFERS
#else
#define SICSLOWPAN_FRAGMENT_BUFFERS 12
#endif
/* REASS_CONTEXTS corresponds to the number of simultaneous
* reassemblies that can be made. NOTE: the first buffer for each
* reassembly is stored in the context since it can be larger than the
* rest of the fragments due to header compression.
**/
#ifdef SICSLOWPAN_CONF_REASS_CONTEXTS
#define SICSLOWPAN_REASS_CONTEXTS SICSLOWPAN_CONF_REASS_CONTEXTS
#else
#define SICSLOWPAN_REASS_CONTEXTS 2
#endif
/* The size of each fragment (IP payload) for the 6lowpan fragmentation */
#ifdef SICSLOWPAN_CONF_FRAGMENT_SIZE
#define SICSLOWPAN_FRAGMENT_SIZE SICSLOWPAN_CONF_FRAGMENT_SIZE
#else
/* The default fragment size (110 bytes for 127-2 bytes frames) */
#define SICSLOWPAN_FRAGMENT_SIZE (127 - 2 - 15)
#endif
/* Assuming that the worst growth for uncompression is 38 bytes */
#define SICSLOWPAN_FIRST_FRAGMENT_SIZE (SICSLOWPAN_FRAGMENT_SIZE + 38)
/* all information needed for reassembly */
struct sicslowpan_frag_info {
/** When reassembling, the source address of the fragments being merged */
linkaddr_t sender;
/** The destination address of the fragments being merged */
linkaddr_t receiver;
/** When reassembling, the tag in the fragments being merged. */
uint16_t tag;
/** Total length of the fragmented packet */
uint16_t len;
/** Current length of reassembled fragments */
uint16_t reassembled_len;
/** Reassembly %process %timer. */
struct timer reass_timer;
/** Fragment size of first fragment */
uint16_t first_frag_len;
/** First fragment - needs a larger buffer since the size is uncompressed size
and we need to know total size to know when we have received last fragment. */
uint8_t first_frag[SICSLOWPAN_FIRST_FRAGMENT_SIZE];
};
static struct sicslowpan_frag_info frag_info[SICSLOWPAN_REASS_CONTEXTS];
struct sicslowpan_frag_buf {
/* the index of the frag_info */
uint8_t index;
/* Fragment offset */
uint8_t offset;
/* Length of this fragment (if zero this buffer is not allocated) */
uint8_t len;
uint8_t data[SICSLOWPAN_FRAGMENT_SIZE];
};
static struct sicslowpan_frag_buf frag_buf[SICSLOWPAN_FRAGMENT_BUFFERS];
/*---------------------------------------------------------------------------*/
static int
clear_fragments(uint8_t frag_info_index)
{
int i, clear_count;
clear_count = 0;
frag_info[frag_info_index].len = 0;
for(i = 0; i < SICSLOWPAN_FRAGMENT_BUFFERS; i++) {
if(frag_buf[i].len > 0 && frag_buf[i].index == frag_info_index) {
/* deallocate the buffer */
frag_buf[i].len = 0;
clear_count++;
}
}
return clear_count;
}
/*---------------------------------------------------------------------------*/
static int
timeout_fragments(int not_context)
{
int i;
int count = 0;
for(i = 0; i < SICSLOWPAN_REASS_CONTEXTS; i++) {
if(frag_info[i].len > 0 && i != not_context &&
timer_expired(&frag_info[i].reass_timer)) {
/* This context can be freed */
count += clear_fragments(i);
}
}
return count;
}
/*---------------------------------------------------------------------------*/
static int
store_fragment(uint8_t index, uint8_t offset)
{
int i;
for(i = 0; i < SICSLOWPAN_FRAGMENT_BUFFERS; i++) {
if(frag_buf[i].len == 0) {
/* copy over the data from packetbuf into the fragment buffer and store offset and len */
frag_buf[i].offset = offset; /* frag offset */
frag_buf[i].len = packetbuf_datalen() - packetbuf_hdr_len;
frag_buf[i].index = index;
memcpy(frag_buf[i].data, packetbuf_ptr + packetbuf_hdr_len,
packetbuf_datalen() - packetbuf_hdr_len);
/* return the length of the stored fragment */
return frag_buf[i].len;
}
}
/* failed */
return -1;
}
/*---------------------------------------------------------------------------*/
/* add a new fragment to the buffer */
static int8_t
add_fragment(uint16_t tag, uint16_t frag_size, uint8_t offset)
{
int i;
int len;
int8_t found = -1;
if(offset == 0) {
/* This is a first fragment - check if we can add this */
for(i = 0; i < SICSLOWPAN_REASS_CONTEXTS; i++) {
/* clear all fragment info with expired timer to free all fragment buffers */
if(frag_info[i].len > 0 && timer_expired(&frag_info[i].reass_timer)) {
clear_fragments(i);
}
/* We use len as indication on used or not used */
if(found < 0 && frag_info[i].len == 0) {
/* We remember the first free fragment info but must continue
the loop to free any other expired fragment buffers. */
found = i;
}
}
if(found < 0) {
LOG_WARN("reassembly: failed to store new fragment session - tag: %d\n", tag);
return -1;
}
/* Found a free fragment info to store data in */
frag_info[found].len = frag_size;
frag_info[found].tag = tag;
linkaddr_copy(&frag_info[found].sender,
packetbuf_addr(PACKETBUF_ADDR_SENDER));
timer_set(&frag_info[found].reass_timer, SICSLOWPAN_REASS_MAXAGE * CLOCK_SECOND / 16);
/* first fragment can not be stored immediately but is moved into
the buffer while uncompressing */
return found;
}
/* This is a N-fragment - should find the info */
for(i = 0; i < SICSLOWPAN_REASS_CONTEXTS; i++) {
if(frag_info[i].tag == tag && frag_info[i].len > 0 &&
linkaddr_cmp(&frag_info[i].sender, packetbuf_addr(PACKETBUF_ADDR_SENDER))) {
/* Tag and Sender match - this must be the correct info to store in */
found = i;
break;
}
}
if(found < 0) {
/* no entry found for storing the new fragment */
LOG_WARN("reassembly: failed to store N-fragment - could not find session - tag: %d offset: %d\n", tag, offset);
return -1;
}
/* i is the index of the reassembly context */
len = store_fragment(i, offset);
if(len < 0 && timeout_fragments(i) > 0) {
len = store_fragment(i, offset);
}
if(len > 0) {
frag_info[i].reassembled_len += len;
return i;
} else {
/* should we also clear all fragments since we failed to store
this fragment? */
LOG_WARN("reassembly: failed to store fragment - packet reassembly will fail tag:%d l\n", frag_info[i].tag);
return -1;
}
}
/*---------------------------------------------------------------------------*/
/* Copy all the fragments that are associated with a specific context
into uip */
static void
copy_frags2uip(int context)
{
int i;
/* Copy from the fragment context info buffer first */
memcpy((uint8_t *)UIP_IP_BUF, (uint8_t *)frag_info[context].first_frag,
frag_info[context].first_frag_len);
for(i = 0; i < SICSLOWPAN_FRAGMENT_BUFFERS; i++) {
/* And also copy all matching fragments */
if(frag_buf[i].len > 0 && frag_buf[i].index == context) {
memcpy((uint8_t *)UIP_IP_BUF + (uint16_t)(frag_buf[i].offset << 3),
(uint8_t *)frag_buf[i].data, frag_buf[i].len);
}
}
/* deallocate all the fragments for this context */
clear_fragments(context);
}
#endif /* SICSLOWPAN_CONF_FRAG */
/* -------------------------------------------------------------------------- */
/*-------------------------------------------------------------------------*/
/* Basic netstack sniffer */
/*-------------------------------------------------------------------------*/
static struct netstack_sniffer *callback = NULL;
void
netstack_sniffer_add(struct netstack_sniffer *s)
{
callback = s;
}
void
netstack_sniffer_remove(struct netstack_sniffer *s)
{
callback = NULL;
}
static void
set_packet_attrs(void)
{
int c = 0;
/* set protocol in NETWORK_ID */
packetbuf_set_attr(PACKETBUF_ATTR_NETWORK_ID, UIP_IP_BUF->proto);
/* assign values to the channel attribute (port or type + code) */
if(UIP_IP_BUF->proto == UIP_PROTO_UDP) {
c = UIP_UDP_BUF_POS(0)->srcport;
if(UIP_UDP_BUF_POS(0)->destport < c) {
c = UIP_UDP_BUF_POS(0)->destport;
}
} else if(UIP_IP_BUF->proto == UIP_PROTO_TCP) {
c = UIP_TCP_BUF->srcport;
if(UIP_TCP_BUF->destport < c) {
c = UIP_TCP_BUF->destport;
}
} else if(UIP_IP_BUF->proto == UIP_PROTO_ICMP6) {
c = UIP_ICMP_BUF->type << 8 | UIP_ICMP_BUF->icode;
}
packetbuf_set_attr(PACKETBUF_ATTR_CHANNEL, c);
/* if(uip_ds6_is_my_addr(&UIP_IP_BUF->srcipaddr)) { */
/* own = 1; */
/* } */
}
#if SICSLOWPAN_COMPRESSION >= SICSLOWPAN_COMPRESSION_IPHC
/** \name variables specific to HC06 and more recent versions
* @{
*/
/** Addresses contexts for IPHC. */
#if SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 0
static struct sicslowpan_addr_context
addr_contexts[SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS];
#endif
/** pointer to an address context. */
static struct sicslowpan_addr_context *context;
/** pointer to the byte where to write next inline field. */
static uint8_t *hc06_ptr;
/* Uncompression of linklocal */
/* 0 -> 16 bytes from packet */
/* 1 -> 2 bytes from prefix - bunch of zeroes and 8 from packet */
/* 2 -> 2 bytes from prefix - 0000::00ff:fe00:XXXX from packet */
/* 3 -> 2 bytes from prefix - infer 8 bytes from lladdr */
/* NOTE: => the uncompress function does change 0xf to 0x10 */
/* NOTE: 0x00 => no-autoconfig => unspecified */
const uint8_t unc_llconf[] = {0x0f,0x28,0x22,0x20};
/* Uncompression of ctx-based */
/* 0 -> 0 bits from packet [unspecified / reserved] */
/* 1 -> 8 bytes from prefix - bunch of zeroes and 8 from packet */
/* 2 -> 8 bytes from prefix - 0000::00ff:fe00:XXXX + 2 from packet */
/* 3 -> 8 bytes from prefix - infer 8 bytes from lladdr */
const uint8_t unc_ctxconf[] = {0x00,0x88,0x82,0x80};
/* Uncompression of ctx-based */
/* 0 -> 0 bits from packet */
/* 1 -> 2 bytes from prefix - bunch of zeroes 5 from packet */
/* 2 -> 2 bytes from prefix - zeroes + 3 from packet */
/* 3 -> 2 bytes from prefix - infer 1 bytes from lladdr */
const uint8_t unc_mxconf[] = {0x0f, 0x25, 0x23, 0x21};
/* Link local prefix */
const uint8_t llprefix[] = {0xfe, 0x80};
/* TTL uncompression values */
static const uint8_t ttl_values[] = {0, 1, 64, 255};
/*--------------------------------------------------------------------*/
/** \name IPHC related functions
* @{ */
/*--------------------------------------------------------------------*/
/** \brief find the context corresponding to prefix ipaddr */
static struct sicslowpan_addr_context*
addr_context_lookup_by_prefix(uip_ipaddr_t *ipaddr)
{
/* Remove code to avoid warnings and save flash if no context is used */
#if SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 0
int i;
for(i = 0; i < SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS; i++) {
if((addr_contexts[i].used == 1) &&
uip_ipaddr_prefixcmp(&addr_contexts[i].prefix, ipaddr, 64)) {
return &addr_contexts[i];
}
}
#endif /* SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 0 */
return NULL;
}
/*--------------------------------------------------------------------*/
/** \brief find the context with the given number */
static struct sicslowpan_addr_context*
addr_context_lookup_by_number(uint8_t number)
{
/* Remove code to avoid warnings and save flash if no context is used */
#if SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 0
int i;
for(i = 0; i < SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS; i++) {
if((addr_contexts[i].used == 1) &&
addr_contexts[i].number == number) {
return &addr_contexts[i];
}
}
#endif /* SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 0 */
return NULL;
}
/*--------------------------------------------------------------------*/
static uint8_t
compress_addr_64(uint8_t bitpos, uip_ipaddr_t *ipaddr, uip_lladdr_t *lladdr)
{
if(uip_is_addr_mac_addr_based(ipaddr, lladdr)) {
return 3 << bitpos; /* 0-bits */
} else if(sicslowpan_is_iid_16_bit_compressable(ipaddr)) {
/* compress IID to 16 bits xxxx::0000:00ff:fe00:XXXX */
memcpy(hc06_ptr, &ipaddr->u16[7], 2);
hc06_ptr += 2;
return 2 << bitpos; /* 16-bits */
} else {
/* do not compress IID => xxxx::IID */
memcpy(hc06_ptr, &ipaddr->u16[4], 8);
hc06_ptr += 8;
return 1 << bitpos; /* 64-bits */
}
}
/*-------------------------------------------------------------------- */
/* Uncompress addresses based on a prefix and a postfix with zeroes in
* between. If the postfix is zero in length it will use the link address
* to configure the IP address (autoconf style).
* pref_post_count takes a byte where the first nibble specify prefix count
* and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
*/
static void
uncompress_addr(uip_ipaddr_t *ipaddr, uint8_t const prefix[],
uint8_t pref_post_count, uip_lladdr_t *lladdr)
{
uint8_t prefcount = pref_post_count >> 4;
uint8_t postcount = pref_post_count & 0x0f;
/* full nibble 15 => 16 */
prefcount = prefcount == 15 ? 16 : prefcount;
postcount = postcount == 15 ? 16 : postcount;
LOG_DBG("uncompression: address %d %d", prefcount, postcount);
if(prefcount > 0) {
memcpy(ipaddr, prefix, prefcount);
}
if(prefcount + postcount < 16) {
memset(&ipaddr->u8[prefcount], 0, 16 - (prefcount + postcount));
}
if(postcount > 0) {
memcpy(&ipaddr->u8[16 - postcount], hc06_ptr, postcount);
if(postcount == 2 && prefcount < 11) {
/* 16 bits uncompression => 0000:00ff:fe00:XXXX */
ipaddr->u8[11] = 0xff;
ipaddr->u8[12] = 0xfe;
}
hc06_ptr += postcount;
} else if (prefcount > 0) {
/* no IID based configuration if no prefix and no data => unspec */
uip_ds6_set_addr_iid(ipaddr, lladdr);
}
LOG_DBG_6ADDR(ipaddr);
LOG_DBG_("\n");
}
/*--------------------------------------------------------------------*/
/**
* \brief Compress IP/UDP header
*
* This function is called by the 6lowpan code to create a compressed
* 6lowpan packet in the packetbuf buffer from a full IPv6 packet in the
* uip_buf buffer.
*
*
* IPHC (RFC 6282)\n
* http://tools.ietf.org/html/
*
* \note We do not support ISA100_UDP header compression
*
* For LOWPAN_UDP compression, we either compress both ports or none.
* General format with LOWPAN_UDP compression is
* \verbatim
* 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |0|1|1|TF |N|HLI|C|S|SAM|M|D|DAM| SCI | DCI | comp. IPv6 hdr|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | compressed IPv6 fields ..... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | LOWPAN_UDP | non compressed UDP fields ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | L4 data ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* \endverbatim
* \note The context number 00 is reserved for the link local prefix.
* For unicast addresses, if we cannot compress the prefix, we neither
* compress the IID.
* \param link_destaddr L2 destination address, needed to compress IP
* dest
* \return 1 if success, else 0
*/
static int
compress_hdr_iphc(linkaddr_t *link_destaddr)
{
uint8_t tmp, iphc0, iphc1, *next_hdr, *next_nhc;
int ext_hdr_len;
struct uip_udp_hdr *udp_buf;
if(LOG_DBG_ENABLED) {
uint16_t ndx;
LOG_DBG("compression: before (%d): ", UIP_IP_BUF->len[1]);
for(ndx = 0; ndx < UIP_IP_BUF->len[1] + 40; ndx++) {
uint8_t data = ((uint8_t *) (UIP_IP_BUF))[ndx];
LOG_DBG_("%02x", data);
}
LOG_DBG_("\n");
}
/* Macro used only internally, during header compression. Checks if there
* is sufficient space in packetbuf before writing any further. */
#define CHECK_BUFFER_SPACE(writelen) do { \
if(hc06_ptr + (writelen) >= PACKETBUF_PAYLOAD_END) { \
LOG_WARN("Not enough packetbuf space to compress header (%u bytes, %u left). Aborting.\n", \
(unsigned)(writelen), (unsigned)(PACKETBUF_PAYLOAD_END - hc06_ptr)); \
return 0; \
} \
} while(0);
hc06_ptr = PACKETBUF_IPHC_BUF + 2;
/* Check if there is enough space for the compressed IPv6 header, in the
* worst case (least compressed case). Extension headers and transport
* layer will be checked when they are compressed. */
CHECK_BUFFER_SPACE(38);
/*
* As we copy some bit-length fields, in the IPHC encoding bytes,
* we sometimes use |=
* If the field is 0, and the current bit value in memory is 1,
* this does not work. We therefore reset the IPHC encoding here
*/
iphc0 = SICSLOWPAN_DISPATCH_IPHC;
iphc1 = 0;
PACKETBUF_IPHC_BUF[2] = 0; /* might not be used - but needs to be cleared */
/*
* Address handling needs to be made first since it might
* cause an extra byte with [ SCI | DCI ]
*
*/
/* check if dest context exists (for allocating third byte) */
/* TODO: fix this so that it remembers the looked up values for
avoiding two lookups - or set the lookup values immediately */
if(addr_context_lookup_by_prefix(&UIP_IP_BUF->destipaddr) != NULL ||
addr_context_lookup_by_prefix(&UIP_IP_BUF->srcipaddr) != NULL) {
/* set context flag and increase hc06_ptr */
LOG_DBG("compression: dest or src ipaddr - setting CID\n");
iphc1 |= SICSLOWPAN_IPHC_CID;
hc06_ptr++;
}
/*
* Traffic class, flow label
* If flow label is 0, compress it. If traffic class is 0, compress it
* We have to process both in the same time as the offset of traffic class
* depends on the presence of version and flow label
*/
/* IPHC format of tc is ECN | DSCP , original is DSCP | ECN */
tmp = (UIP_IP_BUF->vtc << 4) | (UIP_IP_BUF->tcflow >> 4);
tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
if(((UIP_IP_BUF->tcflow & 0x0F) == 0) &&
(UIP_IP_BUF->flow == 0)) {
/* flow label can be compressed */
iphc0 |= SICSLOWPAN_IPHC_FL_C;
if(((UIP_IP_BUF->vtc & 0x0F) == 0) &&
((UIP_IP_BUF->tcflow & 0xF0) == 0)) {
/* compress (elide) all */
iphc0 |= SICSLOWPAN_IPHC_TC_C;
} else {
/* compress only the flow label */
*hc06_ptr = tmp;
hc06_ptr += 1;
}
} else {
/* Flow label cannot be compressed */
if(((UIP_IP_BUF->vtc & 0x0F) == 0) &&
((UIP_IP_BUF->tcflow & 0xF0) == 0)) {
/* compress only traffic class */
iphc0 |= SICSLOWPAN_IPHC_TC_C;
*hc06_ptr = (tmp & 0xc0) |
(UIP_IP_BUF->tcflow & 0x0F);
memcpy(hc06_ptr + 1, &UIP_IP_BUF->flow, 2);
hc06_ptr += 3;
} else {
/* compress nothing */
memcpy(hc06_ptr, &UIP_IP_BUF->vtc, 4);
/* but replace the top byte with the new ECN | DSCP format*/
*hc06_ptr = tmp;
hc06_ptr += 4;
}
}
/* Note that the payload length is always compressed */
/* Next header. We compress it is compressable. */
if(IS_COMPRESSABLE_PROTO(UIP_IP_BUF->proto)) {
iphc0 |= SICSLOWPAN_IPHC_NH_C;
}
/* Add proto header unless it is compressed */
if((iphc0 & SICSLOWPAN_IPHC_NH_C) == 0) {
*hc06_ptr = UIP_IP_BUF->proto;
hc06_ptr += 1;
}
/*
* Hop limit
* if 1: compress, encoding is 01
* if 64: compress, encoding is 10
* if 255: compress, encoding is 11
* else do not compress
*/
switch(UIP_IP_BUF->ttl) {
case 1:
iphc0 |= SICSLOWPAN_IPHC_TTL_1;
break;
case 64:
iphc0 |= SICSLOWPAN_IPHC_TTL_64;
break;
case 255:
iphc0 |= SICSLOWPAN_IPHC_TTL_255;
break;
default:
*hc06_ptr = UIP_IP_BUF->ttl;
hc06_ptr += 1;
break;
}
/* source address - cannot be multicast */
if(uip_is_addr_unspecified(&UIP_IP_BUF->srcipaddr)) {
LOG_DBG("compression: addr unspecified - setting SAC\n");
iphc1 |= SICSLOWPAN_IPHC_SAC;
iphc1 |= SICSLOWPAN_IPHC_SAM_00;
} else if((context = addr_context_lookup_by_prefix(&UIP_IP_BUF->srcipaddr))
!= NULL) {
/* elide the prefix - indicate by CID and set context + SAC */
LOG_DBG("compression: src with context - setting CID & SAC ctx: %d\n",
context->number);
iphc1 |= SICSLOWPAN_IPHC_CID | SICSLOWPAN_IPHC_SAC;
PACKETBUF_IPHC_BUF[2] |= context->number << 4;
/* compession compare with this nodes address (source) */
iphc1 |= compress_addr_64(SICSLOWPAN_IPHC_SAM_BIT,
&UIP_IP_BUF->srcipaddr, &uip_lladdr);
/* No context found for this address */
} else if(uip_is_addr_linklocal(&UIP_IP_BUF->srcipaddr) &&
UIP_IP_BUF->destipaddr.u16[1] == 0 &&
UIP_IP_BUF->destipaddr.u16[2] == 0 &&
UIP_IP_BUF->destipaddr.u16[3] == 0) {
iphc1 |= compress_addr_64(SICSLOWPAN_IPHC_SAM_BIT,
&UIP_IP_BUF->srcipaddr, &uip_lladdr);
} else {
/* send the full address => SAC = 0, SAM = 00 */
iphc1 |= SICSLOWPAN_IPHC_SAM_00; /* 128-bits */
memcpy(hc06_ptr, &UIP_IP_BUF->srcipaddr.u16[0], 16);
hc06_ptr += 16;
}
/* dest address*/
if(uip_is_addr_mcast(&UIP_IP_BUF->destipaddr)) {
/* Address is multicast, try to compress */
iphc1 |= SICSLOWPAN_IPHC_M;
if(sicslowpan_is_mcast_addr_compressable8(&UIP_IP_BUF->destipaddr)) {
iphc1 |= SICSLOWPAN_IPHC_DAM_11;
/* use last byte */
*hc06_ptr = UIP_IP_BUF->destipaddr.u8[15];
hc06_ptr += 1;
} else if(sicslowpan_is_mcast_addr_compressable32(&UIP_IP_BUF->destipaddr)) {
iphc1 |= SICSLOWPAN_IPHC_DAM_10;
/* second byte + the last three */
*hc06_ptr = UIP_IP_BUF->destipaddr.u8[1];
memcpy(hc06_ptr + 1, &UIP_IP_BUF->destipaddr.u8[13], 3);
hc06_ptr += 4;
} else if(sicslowpan_is_mcast_addr_compressable48(&UIP_IP_BUF->destipaddr)) {
iphc1 |= SICSLOWPAN_IPHC_DAM_01;
/* second byte + the last five */
*hc06_ptr = UIP_IP_BUF->destipaddr.u8[1];
memcpy(hc06_ptr + 1, &UIP_IP_BUF->destipaddr.u8[11], 5);
hc06_ptr += 6;
} else {
iphc1 |= SICSLOWPAN_IPHC_DAM_00;
/* full address */
memcpy(hc06_ptr, &UIP_IP_BUF->destipaddr.u8[0], 16);
hc06_ptr += 16;
}
} else {
/* Address is unicast, try to compress */
if((context = addr_context_lookup_by_prefix(&UIP_IP_BUF->destipaddr)) != NULL) {
/* elide the prefix */
iphc1 |= SICSLOWPAN_IPHC_DAC;
PACKETBUF_IPHC_BUF[2] |= context->number;
/* compession compare with link adress (destination) */
iphc1 |= compress_addr_64(SICSLOWPAN_IPHC_DAM_BIT,
&UIP_IP_BUF->destipaddr,
(uip_lladdr_t *)link_destaddr);
/* No context found for this address */
} else if(uip_is_addr_linklocal(&UIP_IP_BUF->destipaddr) &&
UIP_IP_BUF->destipaddr.u16[1] == 0 &&
UIP_IP_BUF->destipaddr.u16[2] == 0 &&
UIP_IP_BUF->destipaddr.u16[3] == 0) {
iphc1 |= compress_addr_64(SICSLOWPAN_IPHC_DAM_BIT,
&UIP_IP_BUF->destipaddr, (uip_lladdr_t *)link_destaddr);
} else {
/* send the full address */
iphc1 |= SICSLOWPAN_IPHC_DAM_00; /* 128-bits */
memcpy(hc06_ptr, &UIP_IP_BUF->destipaddr.u16[0], 16);
hc06_ptr += 16;
}
}
uncomp_hdr_len = UIP_IPH_LEN;
/* Start of ext hdr compression or UDP compression */
/* pick out the next-header position */
next_hdr = &UIP_IP_BUF->proto;
next_nhc = hc06_ptr; /* here we set the next header is compressed. */
ext_hdr_len = 0;
/* reserve the write place of this next header position */
LOG_DBG("compression: first header: %d\n", *next_hdr);
while(next_hdr != NULL && IS_COMPRESSABLE_PROTO(*next_hdr)) {
LOG_DBG("compression: next header: %d\n", *next_hdr);
int proto = -1; /* used for the specific ext hdr */
/* UDP and EXT header compression */
switch(*next_hdr) {
case UIP_PROTO_HBHO:
proto = SICSLOWPAN_NHC_ETX_HDR_HBHO;
case UIP_PROTO_ROUTING:
proto = proto == -1 ? SICSLOWPAN_NHC_ETX_HDR_ROUTING : proto;
case UIP_PROTO_FRAG:
proto = proto == -1 ? SICSLOWPAN_NHC_ETX_HDR_FRAG : proto;
case UIP_PROTO_DESTO:
/* Handle the header here! */
{
struct uip_ext_hdr *ext_hdr =
(struct uip_ext_hdr *) UIP_IPPAYLOAD_BUF_POS(ext_hdr_len);
int len;
proto = proto == -1 ? SICSLOWPAN_NHC_ETX_HDR_DESTO : proto;
/* Len is defined to be in octets from the length byte */
len = (ext_hdr->len << 3) + 8;
LOG_DBG("compression: next header %d (len:%d)\n", *next_hdr, len);
/* pick up the next header */
next_hdr = &ext_hdr->next;
/* If the next header is not compressable we need to reserve the
NHC byte extra - before the next header here. This is due to
next not being elided in that case. */
if(!IS_COMPRESSABLE_PROTO(*next_hdr)) {
CHECK_BUFFER_SPACE(1);
hc06_ptr++;
LOG_DBG("compression: keeping the next header in this ext hdr: %d\n",
ext_hdr->next);
}
/* copy the ext-hdr into the hc06 buffer */
CHECK_BUFFER_SPACE(len);
memcpy(hc06_ptr, ext_hdr, len);
/* modify the len to octets */
ext_hdr = (struct uip_ext_hdr *) hc06_ptr;
ext_hdr->len = len - 2; /* Len should be in bytes from len byte*/
ext_hdr_len += len;
hc06_ptr += len;
uncomp_hdr_len += len;
/* Write this next header - with its NHC header - including flag
to tell if next header is elided in this one also- */
*next_nhc = SICSLOWPAN_NHC_EXT_HDR |
(IS_COMPRESSABLE_PROTO(*next_hdr) ? SICSLOWPAN_NHC_BIT : 0) |
(proto << 1);
/* update the position of the next header */
next_nhc = hc06_ptr;
}
break;
case UIP_PROTO_UDP:
/* allocate a byte for the next header posision as UDP has no next */
hc06_ptr++;
udp_buf = UIP_UDP_BUF_POS(ext_hdr_len);
LOG_DBG("compression: inlined UDP ports on send side: %x, %x\n",
UIP_HTONS(udp_buf->srcport), UIP_HTONS(udp_buf->destport));
/* Mask out the last 4 bits can be used as a mask */
if(((UIP_HTONS(udp_buf->srcport) & 0xfff0) == SICSLOWPAN_UDP_4_BIT_PORT_MIN) &&
((UIP_HTONS(udp_buf->destport) & 0xfff0) == SICSLOWPAN_UDP_4_BIT_PORT_MIN)) {
/* we can compress 12 bits of both source and dest */
*next_nhc = SICSLOWPAN_NHC_UDP_CS_P_11;
LOG_DBG("IPHC: remove 12 b of both source & dest with prefix 0xFOB\n");
CHECK_BUFFER_SPACE(1);
*hc06_ptr =
(uint8_t)((UIP_HTONS(udp_buf->srcport) -
SICSLOWPAN_UDP_4_BIT_PORT_MIN) << 4) +
(uint8_t)((UIP_HTONS(udp_buf->destport) -
SICSLOWPAN_UDP_4_BIT_PORT_MIN));
hc06_ptr += 1;
} else if((UIP_HTONS(udp_buf->destport) & 0xff00) == SICSLOWPAN_UDP_8_BIT_PORT_MIN) {
/* we can compress 8 bits of dest, leave source. */
*next_nhc = SICSLOWPAN_NHC_UDP_CS_P_01;
LOG_DBG("IPHC: leave source, remove 8 bits of dest with prefix 0xF0\n");
CHECK_BUFFER_SPACE(3);
memcpy(hc06_ptr, &udp_buf->srcport, 2);
*(hc06_ptr + 2) =
(uint8_t)((UIP_HTONS(udp_buf->destport) -
SICSLOWPAN_UDP_8_BIT_PORT_MIN));
hc06_ptr += 3;
} else if((UIP_HTONS(udp_buf->srcport) & 0xff00) == SICSLOWPAN_UDP_8_BIT_PORT_MIN) {
/* we can compress 8 bits of src, leave dest. Copy compressed port */
*next_nhc = SICSLOWPAN_NHC_UDP_CS_P_10;
LOG_DBG("IPHC: remove 8 bits of source with prefix 0xF0, leave dest. hch: %i\n", *next_nhc);
CHECK_BUFFER_SPACE(3);
*hc06_ptr =
(uint8_t)((UIP_HTONS(udp_buf->srcport) -
SICSLOWPAN_UDP_8_BIT_PORT_MIN));
memcpy(hc06_ptr + 1, &udp_buf->destport, 2);
hc06_ptr += 3;
} else {
/* we cannot compress. Copy uncompressed ports, full checksum */
*next_nhc = SICSLOWPAN_NHC_UDP_CS_P_00;
LOG_DBG("IPHC: cannot compress UDP headers\n");
CHECK_BUFFER_SPACE(4);
memcpy(hc06_ptr, &udp_buf->srcport, 4);
hc06_ptr += 4;
}
/* always inline the checksum */
CHECK_BUFFER_SPACE(2);
memcpy(hc06_ptr, &udp_buf->udpchksum, 2);
hc06_ptr += 2;
uncomp_hdr_len += UIP_UDPH_LEN;
/* this is the final header. */
next_hdr = NULL;
break;
default:
LOG_ERR("compression: could not handle compression of header");
}
}
if(next_hdr != NULL) {
/* Last header could not be compressed - we assume that this is then OK!*/
/* as the last EXT_HDR should be "uncompressed" and have the next there */
LOG_DBG("compression: last header could is not compressed: %d\n", *next_hdr);
}
/* before the packetbuf_hdr_len operation */
PACKETBUF_IPHC_BUF[0] = iphc0;
PACKETBUF_IPHC_BUF[1] = iphc1;
if(LOG_DBG_ENABLED) {
uint16_t ndx;
LOG_DBG("compression: after (%d): ", (int)(hc06_ptr - packetbuf_ptr));
for(ndx = 0; ndx < hc06_ptr - packetbuf_ptr; ndx++) {
uint8_t data = ((uint8_t *) packetbuf_ptr)[ndx];
LOG_DBG_("%02x", data);
}
LOG_DBG_("\n");
}
packetbuf_hdr_len = hc06_ptr - packetbuf_ptr;
return 1;
}
/*--------------------------------------------------------------------*/
/**
* \brief Uncompress IPHC (i.e., IPHC and LOWPAN_UDP) headers and put
* them in sicslowpan_buf
*
* This function is called by the input function when the dispatch is
* IPHC.
* We %process the packet in the packetbuf buffer, uncompress the header
* fields, and copy the result in the sicslowpan buffer.
* At the end of the decompression, packetbuf_hdr_len and uncompressed_hdr_len
* are set to the appropriate values
*
* \param buf Pointer to the buffer to uncompress the packet into.
* \param ip_len Equal to 0 if the packet is not a fragment (IP length
* is then inferred from the L2 length), non 0 if the packet is a 1st
* fragment.
*/
static void
uncompress_hdr_iphc(uint8_t *buf, uint16_t ip_len)
{
uint8_t tmp, iphc0, iphc1, nhc;
struct uip_ext_hdr *exthdr;
uint8_t* last_nextheader;
uint8_t* ip_payload;
uint8_t ext_hdr_len = 0;
/* at least two byte will be used for the encoding */
hc06_ptr = packetbuf_ptr + packetbuf_hdr_len + 2;
iphc0 = PACKETBUF_IPHC_BUF[0];
iphc1 = PACKETBUF_IPHC_BUF[1];
/* another if the CID flag is set */
if(iphc1 & SICSLOWPAN_IPHC_CID) {
LOG_DBG("uncompression: CID flag set - increase header with one\n");
hc06_ptr++;
}
/* Traffic class and flow label */
if((iphc0 & SICSLOWPAN_IPHC_FL_C) == 0) {
/* Flow label are carried inline */
if((iphc0 & SICSLOWPAN_IPHC_TC_C) == 0) {
/* Traffic class is carried inline */
memcpy(&SICSLOWPAN_IP_BUF(buf)->tcflow, hc06_ptr + 1, 3);
tmp = *hc06_ptr;
hc06_ptr += 4;
/* IPHC format of tc is ECN | DSCP , original is DSCP | ECN */
/* set version, pick highest DSCP bits and set in vtc */
SICSLOWPAN_IP_BUF(buf)->vtc = 0x60 | ((tmp >> 2) & 0x0f);
/* ECN rolled down two steps + lowest DSCP bits at top two bits */
SICSLOWPAN_IP_BUF(buf)->tcflow = ((tmp >> 2) & 0x30) | (tmp << 6) |
(SICSLOWPAN_IP_BUF(buf)->tcflow & 0x0f);
} else {
/* Traffic class is compressed (set version and no TC)*/
SICSLOWPAN_IP_BUF(buf)->vtc = 0x60;
/* highest flow label bits + ECN bits */
SICSLOWPAN_IP_BUF(buf)->tcflow = (*hc06_ptr & 0x0F) |
((*hc06_ptr >> 2) & 0x30);
memcpy(&SICSLOWPAN_IP_BUF(buf)->flow, hc06_ptr + 1, 2);
hc06_ptr += 3;
}
} else {
/* Version is always 6! */
/* Version and flow label are compressed */
if((iphc0 & SICSLOWPAN_IPHC_TC_C) == 0) {
/* Traffic class is inline */
SICSLOWPAN_IP_BUF(buf)->vtc = 0x60 | ((*hc06_ptr >> 2) & 0x0f);
SICSLOWPAN_IP_BUF(buf)->tcflow = ((*hc06_ptr << 6) & 0xC0) | ((*hc06_ptr >> 2) & 0x30);
SICSLOWPAN_IP_BUF(buf)->flow = 0;
hc06_ptr += 1;
} else {
/* Traffic class is compressed */
SICSLOWPAN_IP_BUF(buf)->vtc = 0x60;
SICSLOWPAN_IP_BUF(buf)->tcflow = 0;
SICSLOWPAN_IP_BUF(buf)->flow = 0;
}
}
/* Next Header */
if((iphc0 & SICSLOWPAN_IPHC_NH_C) == 0) {
/* Next header is carried inline */
SICSLOWPAN_IP_BUF(buf)->proto = *hc06_ptr;
LOG_DBG("uncompression: next header inline: %d\n", SICSLOWPAN_IP_BUF(buf)->proto);
hc06_ptr += 1;
}
/* Hop limit */
if((iphc0 & 0x03) != SICSLOWPAN_IPHC_TTL_I) {
SICSLOWPAN_IP_BUF(buf)->ttl = ttl_values[iphc0 & 0x03];
} else {
SICSLOWPAN_IP_BUF(buf)->ttl = *hc06_ptr;
hc06_ptr += 1;
}
/* put the source address compression mode SAM in the tmp var */
tmp = ((iphc1 & SICSLOWPAN_IPHC_SAM_11) >> SICSLOWPAN_IPHC_SAM_BIT) & 0x03;
/* context based compression */
if(iphc1 & SICSLOWPAN_IPHC_SAC) {
uint8_t sci = (iphc1 & SICSLOWPAN_IPHC_CID) ?
PACKETBUF_IPHC_BUF[2] >> 4 : 0;
/* Source address - check context != NULL only if SAM bits are != 0*/
if (tmp != 0) {
context = addr_context_lookup_by_number(sci);
if(context == NULL) {
LOG_ERR("uncompression: error context not found\n");
return;
}
}
/* if tmp == 0 we do not have a context and therefore no prefix */
uncompress_addr(&SICSLOWPAN_IP_BUF(buf)->srcipaddr,
tmp != 0 ? context->prefix : NULL, unc_ctxconf[tmp],
(uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
} else {
/* no compression and link local */
uncompress_addr(&SICSLOWPAN_IP_BUF(buf)->srcipaddr, llprefix, unc_llconf[tmp],
(uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
}
/* Destination address */
/* put the destination address compression mode into tmp */
tmp = ((iphc1 & SICSLOWPAN_IPHC_DAM_11) >> SICSLOWPAN_IPHC_DAM_BIT) & 0x03;
/* multicast compression */
if(iphc1 & SICSLOWPAN_IPHC_M) {
/* context based multicast compression */
if(iphc1 & SICSLOWPAN_IPHC_DAC) {
/* TODO: implement this */
} else {
/* non-context based multicast compression - */
/* DAM_00: 128 bits */
/* DAM_01: 48 bits FFXX::00XX:XXXX:XXXX */
/* DAM_10: 32 bits FFXX::00XX:XXXX */
/* DAM_11: 8 bits FF02::00XX */
uint8_t prefix[] = {0xff, 0x02};
if(tmp > 0 && tmp < 3) {
prefix[1] = *hc06_ptr;
hc06_ptr++;
}
uncompress_addr(&SICSLOWPAN_IP_BUF(buf)->destipaddr, prefix,
unc_mxconf[tmp], NULL);
}
} else {
/* no multicast */
/* Context based */
if(iphc1 & SICSLOWPAN_IPHC_DAC) {
uint8_t dci = (iphc1 & SICSLOWPAN_IPHC_CID) ? PACKETBUF_IPHC_BUF[2] & 0x0f : 0;
context = addr_context_lookup_by_number(dci);
/* all valid cases below need the context! */
if(context == NULL) {
LOG_ERR("uncompression: error context not found\n");
return;
}
uncompress_addr(&SICSLOWPAN_IP_BUF(buf)->destipaddr, context->prefix,
unc_ctxconf[tmp],
(uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_RECEIVER));
} else {
/* not context based => link local M = 0, DAC = 0 - same as SAC */
uncompress_addr(&SICSLOWPAN_IP_BUF(buf)->destipaddr, llprefix,
unc_llconf[tmp],
(uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_RECEIVER));
}
}
uncomp_hdr_len += UIP_IPH_LEN;
/* Next header processing - continued */
nhc = iphc0 & SICSLOWPAN_IPHC_NH_C;
/* The next header is compressed, NHC is following */
last_nextheader = &SICSLOWPAN_IP_BUF(buf)->proto;
ip_payload = SICSLOWPAN_IPPAYLOAD_BUF(buf);
while(nhc && (*hc06_ptr & SICSLOWPAN_NHC_MASK) == SICSLOWPAN_NHC_EXT_HDR) {
uint8_t eid = (*hc06_ptr & 0x0e) >> 1;
/* next header compression flag */
uint8_t nh = (*hc06_ptr & 0x01);
uint8_t next = 0;
uint8_t len;
uint8_t proto;
nhc = nh;
hc06_ptr++;
if(!nh) {
next = *hc06_ptr;
hc06_ptr++;
LOG_DBG("uncompression: next header is inlined. Next: %d\n", next);
}
len = *hc06_ptr;
hc06_ptr++;
LOG_DBG("uncompression: found ext header id: %d next: %d len: %d\n", eid, next, len);
switch(eid) {
case SICSLOWPAN_NHC_ETX_HDR_HBHO:
proto = UIP_PROTO_HBHO;
break;
case SICSLOWPAN_NHC_ETX_HDR_ROUTING:
proto = UIP_PROTO_ROUTING;
break;
case SICSLOWPAN_NHC_ETX_HDR_FRAG:
proto = UIP_PROTO_FRAG;
break;
case SICSLOWPAN_NHC_ETX_HDR_DESTO:
proto = UIP_PROTO_DESTO;
break;
default:
LOG_DBG("uncompression: error unsupported ext header\n");
return;
}
*last_nextheader = proto;
/* uncompress the extension header */
exthdr = (struct uip_ext_hdr *)ip_payload;
exthdr->len = (2 + len) / 8 - 1;
exthdr->next = next;
last_nextheader = &exthdr->next;
memcpy((uint8_t*)exthdr + 2, hc06_ptr, len);
hc06_ptr += len;
uncomp_hdr_len += (exthdr->len + 1) * 8;
ip_payload += (exthdr->len + 1) * 8;
ext_hdr_len += (exthdr->len + 1) * 8;
LOG_DBG("uncompression: %d len: %d exhdrlen: %d (calc: %d)\n",
proto, len, exthdr->len, (exthdr->len + 1) * 8);
}
/* The next header is compressed, NHC is following */
if(nhc && (*hc06_ptr & SICSLOWPAN_NHC_UDP_MASK) == SICSLOWPAN_NHC_UDP_ID) {
struct uip_udp_hdr *udp_buf = (struct uip_udp_hdr *)ip_payload;
uint16_t udp_len;
uint8_t checksum_compressed;
*last_nextheader = UIP_PROTO_UDP;
checksum_compressed = *hc06_ptr & SICSLOWPAN_NHC_UDP_CHECKSUMC;
LOG_DBG("uncompression: incoming header value: %i\n", *hc06_ptr);
switch(*hc06_ptr & SICSLOWPAN_NHC_UDP_CS_P_11) {
case SICSLOWPAN_NHC_UDP_CS_P_00:
/* 1 byte for NHC, 4 byte for ports, 2 bytes chksum */
memcpy(&udp_buf->srcport, hc06_ptr + 1, 2);
memcpy(&udp_buf->destport, hc06_ptr + 3, 2);
LOG_DBG("uncompression: UDP ports (ptr+5): %x, %x\n",
UIP_HTONS(udp_buf->srcport),
UIP_HTONS(udp_buf->destport));
hc06_ptr += 5;
break;
case SICSLOWPAN_NHC_UDP_CS_P_01:
/* 1 byte for NHC + source 16bit inline, dest = 0xF0 + 8 bit inline */
LOG_DBG("uncompression: destination address\n");
memcpy(&udp_buf->srcport, hc06_ptr + 1, 2);
udp_buf->destport = UIP_HTONS(SICSLOWPAN_UDP_8_BIT_PORT_MIN + (*(hc06_ptr + 3)));
LOG_DBG("uncompression: UDP ports (ptr+4): %x, %x\n",
UIP_HTONS(udp_buf->srcport), UIP_HTONS(udp_buf->destport));
hc06_ptr += 4;
break;
case SICSLOWPAN_NHC_UDP_CS_P_10:
/* 1 byte for NHC + source = 0xF0 + 8bit inline, dest = 16 bit inline*/
LOG_DBG("uncompression: source address\n");
udp_buf->srcport = UIP_HTONS(SICSLOWPAN_UDP_8_BIT_PORT_MIN +
(*(hc06_ptr + 1)));
memcpy(&udp_buf->destport, hc06_ptr + 2, 2);
LOG_DBG("uncompression: UDP ports (ptr+4): %x, %x\n",
UIP_HTONS(udp_buf->srcport), UIP_HTONS(udp_buf->destport));
hc06_ptr += 4;
break;
case SICSLOWPAN_NHC_UDP_CS_P_11:
/* 1 byte for NHC, 1 byte for ports */
udp_buf->srcport = UIP_HTONS(SICSLOWPAN_UDP_4_BIT_PORT_MIN +
(*(hc06_ptr + 1) >> 4));
udp_buf->destport = UIP_HTONS(SICSLOWPAN_UDP_4_BIT_PORT_MIN +
((*(hc06_ptr + 1)) & 0x0F));
LOG_DBG("uncompression: UDP ports (ptr+2): %x, %x\n",
UIP_HTONS(udp_buf->srcport), UIP_HTONS(udp_buf->destport));
hc06_ptr += 2;
break;
default:
LOG_DBG("uncompression: error unsupported UDP compression\n");
return;
}
if(!checksum_compressed) { /* has_checksum, default */
memcpy(&udp_buf->udpchksum, hc06_ptr, 2);
hc06_ptr += 2;
LOG_DBG("uncompression: checksum included\n");
} else {
LOG_DBG("uncompression: checksum *NOT* included\n");
}
/* length field in UDP header (8 byte header + payload) */
udp_len = 8 + packetbuf_datalen() - (hc06_ptr - packetbuf_ptr);
udp_buf->udplen = UIP_HTONS(ip_len == 0 ? udp_len :
ip_len - UIP_IPH_LEN - ext_hdr_len);
LOG_DBG("uncompression: UDP length: %u (ext: %u) ip_len: %d udp_len: %d\n",
UIP_HTONS(udp_buf->udplen), ext_hdr_len, ip_len, udp_len);
uncomp_hdr_len += UIP_UDPH_LEN;
}
packetbuf_hdr_len = hc06_ptr - packetbuf_ptr;
/* IP length field. */
if(ip_len == 0) {
int len = packetbuf_datalen() - packetbuf_hdr_len + uncomp_hdr_len - UIP_IPH_LEN;
LOG_DBG("uncompression: IP payload length: %d. %u - %u + %u - %u\n", len,
packetbuf_datalen(), packetbuf_hdr_len, uncomp_hdr_len, UIP_IPH_LEN);
/* This is not a fragmented packet */
SICSLOWPAN_IP_BUF(buf)->len[0] = len >> 8;
SICSLOWPAN_IP_BUF(buf)->len[1] = len & 0x00FF;
} else {
/* This is a 1st fragment */
SICSLOWPAN_IP_BUF(buf)->len[0] = (ip_len - UIP_IPH_LEN) >> 8;
SICSLOWPAN_IP_BUF(buf)->len[1] = (ip_len - UIP_IPH_LEN) & 0x00FF;
}
}
/** @} */
#endif /* SICSLOWPAN_COMPRESSION >= SICSLOWPAN_COMPRESSION_IPHC */
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_6LORH
/*--------------------------------------------------------------------*/
/**
* \brief Adds Paging dispatch byte
*/
static void
add_paging_dispatch(uint8_t page)
{
/* Add paging dispatch to Page 1 */
PACKETBUF_6LO_PTR[PACKETBUF_6LO_DISPATCH] = SICSLOWPAN_DISPATCH_PAGING | (page & 0x0f);
packetbuf_hdr_len++;
}
/*--------------------------------------------------------------------*/
/**
* \brief Adds 6lorh headers before IPHC
*/
static void
add_6lorh_hdr(void)
{
/* 6LoRH is not implemented yet */
}
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_6LORH */
/*--------------------------------------------------------------------*/
/**
* \brief Digest 6lorh headers before IPHC
*/
static void
digest_paging_dispatch(void)
{
/* Is this a paging dispatch? */
if((PACKETBUF_6LO_PTR[PACKETBUF_6LO_DISPATCH] & SICSLOWPAN_DISPATCH_PAGING_MASK) == SICSLOWPAN_DISPATCH_PAGING) {
/* Parse page number */
curr_page = PACKETBUF_6LO_PTR[PACKETBUF_6LO_DISPATCH] & 0x0f;
packetbuf_hdr_len++;
}
}
/*--------------------------------------------------------------------*/
/**
* \brief Digest 6lorh headers before IPHC
*/
static void
digest_6lorh_hdr(void)
{
/* 6LoRH is not implemented yet */
}
/*--------------------------------------------------------------------*/
/** \name IPv6 dispatch "compression" function
* @{ */
/*--------------------------------------------------------------------*/
/* \brief Packets "Compression" when only IPv6 dispatch is used
*
* There is no compression in this case, all fields are sent
* inline. We just add the IPv6 dispatch byte before the packet.
* \verbatim
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | IPv6 Dsp | IPv6 header and payload ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* \endverbatim
*/
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPV6
static void
compress_hdr_ipv6(linkaddr_t *link_destaddr)
{
*packetbuf_ptr = SICSLOWPAN_DISPATCH_IPV6;
packetbuf_hdr_len += SICSLOWPAN_IPV6_HDR_LEN;
memcpy(packetbuf_ptr + packetbuf_hdr_len, UIP_IP_BUF, UIP_IPH_LEN);
packetbuf_hdr_len += UIP_IPH_LEN;
uncomp_hdr_len += UIP_IPH_LEN;
return;
}
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPV6 */
/** @} */
/*--------------------------------------------------------------------*/
/** \name Input/output functions common to all compression schemes
* @{ */
/*--------------------------------------------------------------------*/
/**
* Callback function for the MAC packet sent callback
*/
static void
packet_sent(void *ptr, int status, int transmissions)
{
const linkaddr_t *dest;
if(callback != NULL) {
callback->output_callback(status);
}
last_tx_status = status;
/* What follows only applies to unicast */
dest = packetbuf_addr(PACKETBUF_ADDR_RECEIVER);
if(linkaddr_cmp(dest, &linkaddr_null)) {
return;
}
/* Update neighbor link statistics */
link_stats_packet_sent(dest, status, transmissions);
/* Call routing protocol link callback */
NETSTACK_ROUTING.link_callback(dest, status, transmissions);
/* DS6 callback, used for UIP_DS6_LL_NUD */
uip_ds6_link_callback(status, transmissions);
}
/*--------------------------------------------------------------------*/
/**
* \brief This function is called by the 6lowpan code to send out a
* packet.
* \param dest the link layer destination address of the packet
*/
static void
send_packet(linkaddr_t *dest)
{
/* Set the link layer destination address for the packet as a
* packetbuf attribute. The MAC layer can access the destination
* address with the function packetbuf_addr(PACKETBUF_ADDR_RECEIVER).
*/
packetbuf_set_addr(PACKETBUF_ADDR_RECEIVER, dest);
#if NETSTACK_CONF_BRIDGE_MODE
/* This needs to be explicitly set here for bridge mode to work */
packetbuf_set_addr(PACKETBUF_ADDR_SENDER,(void*)&uip_lladdr);
#endif
/* Provide a callback function to receive the result of
a packet transmission. */
NETSTACK_MAC.send(&packet_sent, NULL);
/* If we are sending multiple packets in a row, we need to let the
watchdog know that we are still alive. */
watchdog_periodic();
}
#if SICSLOWPAN_CONF_FRAG
/*--------------------------------------------------------------------*/
/**
* \brief This function is called by the 6lowpan code to copy a fragment's
* payload from uIP and send it down the stack.
* \param uip_offset the offset in the uIP buffer where to copy the payload from
* \param dest the link layer destination address of the packet
* \return 1 if success, 0 otherwise
*/
static int
fragment_copy_payload_and_send(uint16_t uip_offset, linkaddr_t *dest) {
struct queuebuf *q;
/* Now copy fragment payload from uip_buf */
memcpy(packetbuf_ptr + packetbuf_hdr_len,
(uint8_t *)UIP_IP_BUF + uip_offset, packetbuf_payload_len);
packetbuf_set_datalen(packetbuf_payload_len + packetbuf_hdr_len);
/* Backup packetbuf to queuebuf. Enables preserving attributes for all framgnets */
q = queuebuf_new_from_packetbuf();
if(q == NULL) {
LOG_WARN("output: could not allocate queuebuf, dropping fragment\n");
return 0;
}
/* Send fragment */
send_packet(dest);
/* Restore packetbuf from queuebuf */
queuebuf_to_packetbuf(q);
queuebuf_free(q);
/* Check tx result. */
if((last_tx_status == MAC_TX_COLLISION) ||
(last_tx_status == MAC_TX_ERR) ||
(last_tx_status == MAC_TX_ERR_FATAL)) {
LOG_ERR("output: error in fragment tx, dropping subsequent fragments.\n");
return 0;
}
return 1;
}
#endif /* SICSLOWPAN_CONF_FRAG */
/*--------------------------------------------------------------------*/
/** \brief Take an IP packet and format it to be sent on an 802.15.4
* network using 6lowpan.
* \param localdest The MAC address of the destination
*
* The IP packet is initially in uip_buf. Its header is compressed
* and if necessary it is fragmented. The resulting
* packet/fragments are put in packetbuf and delivered to the 802.15.4
* MAC.
*/
static uint8_t
output(const linkaddr_t *localdest)
{
int frag_needed;
/* The MAC address of the destination of the packet */
linkaddr_t dest;
/* init */
uncomp_hdr_len = 0;
packetbuf_hdr_len = 0;
/* reset packetbuf buffer */
packetbuf_clear();
packetbuf_ptr = packetbuf_dataptr();
if(callback) {
/* call the attribution when the callback comes, but set attributes
here ! */
set_packet_attrs();
}
/*
* The destination address will be tagged to each outbound
* packet. If the argument localdest is NULL, we are sending a
* broadcast packet.
*/
if(localdest == NULL) {
linkaddr_copy(&dest, &linkaddr_null);
} else {
linkaddr_copy(&dest, localdest);
}
LOG_INFO("output: sending IPv6 packet with len %d\n", uip_len);
/* copy over the retransmission count from uipbuf attributes */
packetbuf_set_attr(PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS,
uipbuf_get_attr(UIPBUF_ATTR_MAX_MAC_TRANSMISSIONS));
/* Calculate NETSTACK_FRAMER's header length, that will be added in the NETSTACK_MAC */
packetbuf_set_addr(PACKETBUF_ADDR_RECEIVER, &dest);
#if LLSEC802154_USES_AUX_HEADER
/* copy LLSEC level */
packetbuf_set_attr(PACKETBUF_ATTR_SECURITY_LEVEL,
uipbuf_get_attr(UIPBUF_ATTR_LLSEC_LEVEL));
#if LLSEC802154_USES_EXPLICIT_KEYS
packetbuf_set_attr(PACKETBUF_ATTR_KEY_INDEX,
uipbuf_get_attr(UIPBUF_ATTR_LLSEC_KEY_ID));
#endif /* LLSEC802154_USES_EXPLICIT_KEYS */
#endif /* LLSEC802154_USES_AUX_HEADER */
mac_max_payload = NETSTACK_MAC.max_payload();
if(mac_max_payload <= 0) {
/* Framing failed, drop packet */
LOG_WARN("output: failed to calculate payload size - dropping packet\n");
return 0;
}
/* Try to compress the headers */
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPV6
compress_hdr_ipv6(&dest);
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPV6 */
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_6LORH
/* Add 6LoRH headers before IPHC. Only needed on routed traffic
(non link-local). */
if(!uip_is_addr_linklocal(&UIP_IP_BUF->destipaddr)) {
add_paging_dispatch(1);
add_6lorh_hdr();
}
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_6LORH */
#if SICSLOWPAN_COMPRESSION >= SICSLOWPAN_COMPRESSION_IPHC
if(compress_hdr_iphc(&dest) == 0) {
/* Warning should already be issued by function above */
return 0;
}
#endif /* SICSLOWPAN_COMPRESSION >= SICSLOWPAN_COMPRESSION_IPHC */
/* Use the mac_max_payload to understand what is the max payload in a MAC
* packet. We calculate it here only to make a better decision of whether
* the outgoing packet needs to be fragmented or not. */
packetbuf_set_addr(PACKETBUF_ADDR_RECEIVER, &dest);
frag_needed = (int)uip_len - (int)uncomp_hdr_len + (int)packetbuf_hdr_len > mac_max_payload;
LOG_INFO("output: header len %d -> %d, total len %d -> %d, MAC max payload %d, frag_needed %d\n",
uncomp_hdr_len, packetbuf_hdr_len,
uip_len, uip_len - uncomp_hdr_len + packetbuf_hdr_len,
mac_max_payload, frag_needed);
if(frag_needed) {
#if SICSLOWPAN_CONF_FRAG
/* Number of bytes processed. */
uint16_t processed_ip_out_len;
uint16_t frag_tag;
int curr_frag = 0;
/*
* The outbound IPv6 packet is too large to fit into a single 15.4
* packet, so we fragment it into multiple packets and send them.
* The first fragment contains frag1 dispatch, then IPv6/IPHC/HC_UDP
* dispatchs/headers and IPv6 payload (with len multiple of 8 bytes).
* The subsequent fragments contain the FRAGN dispatch and more of the
* IPv6 payload (still multiple of 8 bytes, except for the last fragment)
*/
/* Total IPv6 payload */
int total_payload = (uip_len - uncomp_hdr_len);
/* IPv6 payload that goes to first fragment */
int frag1_payload = (mac_max_payload - packetbuf_hdr_len - SICSLOWPAN_FRAG1_HDR_LEN) & 0xfffffff8;
/* max IPv6 payload in each FRAGN. Must be multiple of 8 bytes */
int fragn_max_payload = (mac_max_payload - SICSLOWPAN_FRAGN_HDR_LEN) & 0xfffffff8;
/* max IPv6 payload in the last fragment. Needs not be multiple of 8 bytes */
int last_fragn_max_payload = mac_max_payload - SICSLOWPAN_FRAGN_HDR_LEN;
/* sum of all IPv6 payload that goes to non-first and non-last fragments */
int middle_fragn_total_payload = MAX(total_payload - frag1_payload - last_fragn_max_payload, 0);
/* Ceiling of: 2 + middle_fragn_total_payload / fragn_max_payload */
int fragment_count = 2;
if(middle_fragn_total_payload > 0) {
fragment_count += 1 + (middle_fragn_total_payload - 1) / fragn_max_payload;
}
int freebuf = queuebuf_numfree() - 1;
LOG_INFO("output: fragmentation needed, fragments: %u, free queuebufs: %u\n",
fragment_count, freebuf);
if(freebuf < fragment_count) {
LOG_WARN("output: dropping packet, not enough free bufs (needed: %u, free: %u)\n",
fragment_count, freebuf);
return 0;
}
if(frag1_payload < 0) {
/* The current implementation requires that all headers fit in the first
* fragment. Here is a corner case where the header did fit packetbuf
* but do no longer fit after truncating for a length multiple of 8. */
LOG_WARN("output: compressed header does not fit first fragment\n");
return 0;
}
/* Reset last tx status -- MAC layers most often call packet_sent asynchrously */
last_tx_status = MAC_TX_OK;
/* Update fragment tag */
frag_tag = my_tag++;
/* Move IPHC/IPv6 header to make room for FRAG1 header */
memmove(packetbuf_ptr + SICSLOWPAN_FRAG1_HDR_LEN, packetbuf_ptr, packetbuf_hdr_len);
packetbuf_hdr_len += SICSLOWPAN_FRAG1_HDR_LEN;
/* Set FRAG1 header */
SET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_DISPATCH_SIZE,
((SICSLOWPAN_DISPATCH_FRAG1 << 8) | uip_len));
SET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_TAG, frag_tag);
/* Set frag1 payload len. Was already caulcated earlier as frag1_payload */
packetbuf_payload_len = frag1_payload;
/* Copy payload from uIP and send fragment */
/* Send fragment */
LOG_INFO("output: fragment %d/%d (tag %d, payload %d)\n",
curr_frag + 1, fragment_count,
frag_tag, packetbuf_payload_len);
if(fragment_copy_payload_and_send(uncomp_hdr_len, &dest) == 0) {
return 0;
}
/* Now prepare for subsequent fragments. */
/* FRAGN header: tag was already set at FRAG1. Now set dispatch for all FRAGN */
packetbuf_hdr_len = SICSLOWPAN_FRAGN_HDR_LEN;
SET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_DISPATCH_SIZE,
((SICSLOWPAN_DISPATCH_FRAGN << 8) | uip_len));
/* Keep track of the total length of data sent */
processed_ip_out_len = uncomp_hdr_len + packetbuf_payload_len;
/* Create and send subsequent fragments. */
while(processed_ip_out_len < uip_len) {
curr_frag++;
/* FRAGN header: set offset for this fragment */
PACKETBUF_FRAG_PTR[PACKETBUF_FRAG_OFFSET] = processed_ip_out_len >> 3;
/* Calculate fragment len */
if(uip_len - processed_ip_out_len > last_fragn_max_payload) {
/* Not last fragment, send max FRAGN payload */
packetbuf_payload_len = fragn_max_payload;
} else {
/* last fragment */
packetbuf_payload_len = uip_len - processed_ip_out_len;
}
/* Copy payload from uIP and send fragment */
/* Send fragment */
LOG_INFO("output: fragment %d/%d (tag %d, payload %d, offset %d)\n",
curr_frag + 1, fragment_count,
frag_tag, packetbuf_payload_len, processed_ip_out_len);
if(fragment_copy_payload_and_send(processed_ip_out_len, &dest) == 0) {
return 0;
}
processed_ip_out_len += packetbuf_payload_len;
}
#else /* SICSLOWPAN_CONF_FRAG */
LOG_ERR("output: Packet too large to be sent without fragmentation support; dropping packet\n");
return 0;
#endif /* SICSLOWPAN_CONF_FRAG */
} else {
/*
* The packet does not need to be fragmented
* copy "payload" and send
*/
memcpy(packetbuf_ptr + packetbuf_hdr_len, (uint8_t *)UIP_IP_BUF + uncomp_hdr_len,
uip_len - uncomp_hdr_len);
packetbuf_set_datalen(uip_len - uncomp_hdr_len + packetbuf_hdr_len);
send_packet(&dest);
}
return 1;
}
/*--------------------------------------------------------------------*/
/** \brief Process a received 6lowpan packet.
*
* The 6lowpan packet is put in packetbuf by the MAC. If its a frag1 or
* a non-fragmented packet we first uncompress the IP header. The
* 6lowpan payload and possibly the uncompressed IP header are then
* copied in siclowpan_buf. If the IP packet is complete it is copied
* to uip_buf and the IP layer is called.
*
* \note We do not check for overlapping sicslowpan fragments
* (it is a SHALL in the RFC 4944 and should never happen)
*/
static void
input(void)
{
/* size of the IP packet (read from fragment) */
uint16_t frag_size = 0;
/* offset of the fragment in the IP packet */
uint8_t frag_offset = 0;
uint8_t *buffer;
#if SICSLOWPAN_CONF_FRAG
uint8_t is_fragment = 0;
int8_t frag_context = 0;
/* tag of the fragment */
uint16_t frag_tag = 0;
uint8_t first_fragment = 0, last_fragment = 0;
#endif /*SICSLOWPAN_CONF_FRAG*/
/* Update link statistics */
link_stats_input_callback(packetbuf_addr(PACKETBUF_ADDR_SENDER));
/* init */
uncomp_hdr_len = 0;
packetbuf_hdr_len = 0;
/* The MAC puts the 15.4 payload inside the packetbuf data buffer */
packetbuf_ptr = packetbuf_dataptr();
if(packetbuf_datalen() == 0) {
LOG_WARN("input: empty packet\n");
return;
}
/* Clear uipbuf and set default attributes */
uipbuf_clear();
/* This is default uip_buf since we assume that this is not fragmented */
buffer = (uint8_t *)UIP_IP_BUF;
/* Save the RSSI of the incoming packet in case the upper layer will
want to query us for it later. */
last_rssi = (signed short)packetbuf_attr(PACKETBUF_ATTR_RSSI);
#if SICSLOWPAN_CONF_FRAG
/*
* Since we don't support the mesh and broadcast header, the first header
* we look for is the fragmentation header
*/
switch((GET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_DISPATCH_SIZE) >> 8) & SICSLOWPAN_DISPATCH_FRAG_MASK) {
case SICSLOWPAN_DISPATCH_FRAG1:
frag_offset = 0;
frag_size = GET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_DISPATCH_SIZE) & 0x07ff;
frag_tag = GET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_TAG);
packetbuf_hdr_len += SICSLOWPAN_FRAG1_HDR_LEN;
first_fragment = 1;
is_fragment = 1;
LOG_INFO("input: received first element of a fragmented packet (tag %d, len %d)\n",
frag_tag, frag_size);
/* Add the fragment to the fragmentation context */
frag_context = add_fragment(frag_tag, frag_size, frag_offset);
if(frag_context == -1) {
LOG_ERR("input: failed to allocate new reassembly context\n");
return;
}
buffer = frag_info[frag_context].first_frag;
break;
case SICSLOWPAN_DISPATCH_FRAGN:
/*
* set offset, tag, size
* Offset is in units of 8 bytes
*/
frag_offset = PACKETBUF_FRAG_PTR[PACKETBUF_FRAG_OFFSET];
frag_tag = GET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_TAG);
frag_size = GET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_DISPATCH_SIZE) & 0x07ff;
packetbuf_hdr_len += SICSLOWPAN_FRAGN_HDR_LEN;
/* Add the fragment to the fragmentation context (this will also
copy the payload) */
frag_context = add_fragment(frag_tag, frag_size, frag_offset);
if(frag_context == -1) {
LOG_ERR("input: reassembly context not found (tag %d)\n", frag_tag);
return;
}
/* Ok - add_fragment will store the fragment automatically - so
we should not store more */
buffer = NULL;
if(frag_info[frag_context].reassembled_len >= frag_size) {
last_fragment = 1;
}
is_fragment = 1;
break;
default:
break;
}
if(is_fragment && !first_fragment) {
/* this is a FRAGN, skip the header compression dispatch section */
goto copypayload;
}
#endif /* SICSLOWPAN_CONF_FRAG */
/* First, process 6LoRH headers */
curr_page = 0;
digest_paging_dispatch();
if(curr_page == 1) {
LOG_INFO("input: page 1, 6LoRH\n");
digest_6lorh_hdr();
} else if (curr_page > 1) {
LOG_ERR("input: page %u not supported\n", curr_page);
return;
}
/* Process next dispatch and headers */
if((PACKETBUF_6LO_PTR[PACKETBUF_6LO_DISPATCH] & SICSLOWPAN_DISPATCH_IPHC_MASK) == SICSLOWPAN_DISPATCH_IPHC) {
LOG_DBG("uncompression: IPHC dispatch\n");
uncompress_hdr_iphc(buffer, frag_size);
} else if(PACKETBUF_6LO_PTR[PACKETBUF_6LO_DISPATCH] == SICSLOWPAN_DISPATCH_IPV6) {
LOG_DBG("uncompression: IPV6 dispatch\n");
packetbuf_hdr_len += SICSLOWPAN_IPV6_HDR_LEN;
/* Put uncompressed IP header in sicslowpan_buf. */
memcpy(buffer, packetbuf_ptr + packetbuf_hdr_len, UIP_IPH_LEN);
/* Update uncomp_hdr_len and packetbuf_hdr_len. */
packetbuf_hdr_len += UIP_IPH_LEN;
uncomp_hdr_len += UIP_IPH_LEN;
} else {
LOG_ERR("uncompression: unknown dispatch: 0x%02x\n",
PACKETBUF_6LO_PTR[PACKETBUF_6LO_DISPATCH] & SICSLOWPAN_DISPATCH_IPHC_MASK);
return;
}
#if SICSLOWPAN_CONF_FRAG
copypayload:
#endif /*SICSLOWPAN_CONF_FRAG*/
/*
* copy "payload" from the packetbuf buffer to the sicslowpan_buf
* if this is a first fragment or not fragmented packet,
* we have already copied the compressed headers, uncomp_hdr_len
* and packetbuf_hdr_len are non 0, frag_offset is.
* If this is a subsequent fragment, this is the contrary.
*/
if(packetbuf_datalen() < packetbuf_hdr_len) {
LOG_ERR("input: packet dropped due to header > total packet\n");
return;
}
packetbuf_payload_len = packetbuf_datalen() - packetbuf_hdr_len;
#if SICSLOWPAN_CONF_FRAG
if(is_fragment) {
LOG_INFO("input: fragment (tag %d, payload %d, offset %d) -- %u %u\n",
frag_tag, packetbuf_payload_len, frag_offset << 3, packetbuf_datalen(), packetbuf_hdr_len);
}
#endif /*SICSLOWPAN_CONF_FRAG*/
/* Sanity-check size of incoming packet to avoid buffer overflow */
{
int req_size = uncomp_hdr_len + (uint16_t)(frag_offset << 3)
+ packetbuf_payload_len;
if(req_size > sizeof(uip_buf)) {
LOG_ERR(
"input: packet dropped, minimum required IP_BUF size: %d+%d+%d=%d (current size: %u)\n",
uncomp_hdr_len, (uint16_t)(frag_offset << 3),
packetbuf_payload_len, req_size, (unsigned)sizeof(uip_buf));
return;
}
}
/* copy the payload if buffer is non-null - which is only the case with first fragment
or packets that are non fragmented */
if(buffer != NULL) {
memcpy((uint8_t *)buffer + uncomp_hdr_len, packetbuf_ptr + packetbuf_hdr_len, packetbuf_payload_len);
}
/* update processed_ip_in_len if fragment, sicslowpan_len otherwise */
#if SICSLOWPAN_CONF_FRAG
if(frag_size > 0) {
/* Add the size of the header only for the first fragment. */
if(first_fragment != 0) {
frag_info[frag_context].reassembled_len = uncomp_hdr_len + packetbuf_payload_len;
frag_info[frag_context].first_frag_len = uncomp_hdr_len + packetbuf_payload_len;
}
/* For the last fragment, we are OK if there is extrenous bytes at
the end of the packet. */
if(last_fragment != 0) {
frag_info[frag_context].reassembled_len = frag_size;
/* copy to uip */
copy_frags2uip(frag_context);
}
}
/*
* If we have a full IP packet in sicslowpan_buf, deliver it to
* the IP stack
*/
if(!is_fragment || last_fragment) {
/* packet is in uip already - just set length */
if(is_fragment != 0 && last_fragment != 0) {
uip_len = frag_size;
} else {
uip_len = packetbuf_payload_len + uncomp_hdr_len;
}
#else
uip_len = packetbuf_payload_len + uncomp_hdr_len;
#endif /* SICSLOWPAN_CONF_FRAG */
LOG_INFO("input: received IPv6 packet with len %d\n",
uip_len);
if(LOG_DBG_ENABLED) {
uint16_t ndx;
LOG_DBG("uncompression: after (%u):", UIP_IP_BUF->len[1]);
for (ndx = 0; ndx < UIP_IP_BUF->len[1] + 40; ndx++) {
uint8_t data = ((uint8_t *) (UIP_IP_BUF))[ndx];
LOG_DBG_("%02x", data);
}
LOG_DBG_("\n");
}
/* if callback is set then set attributes and call */
if(callback) {
set_packet_attrs();
callback->input_callback();
}
#if LLSEC802154_USES_AUX_HEADER
/*
* Assuming that the last packet in packetbuf is containing
* the LLSEC state so that it can be copied to uipbuf.
*/
uipbuf_set_attr(UIPBUF_ATTR_LLSEC_LEVEL,
packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL));
#if LLSEC802154_USES_EXPLICIT_KEYS
uipbuf_set_attr(UIPBUF_ATTR_LLSEC_KEY_ID,
packetbuf_attr(PACKETBUF_ATTR_KEY_INDEX));
#endif /* LLSEC802154_USES_EXPLICIT_KEYS */
#endif /* LLSEC802154_USES_AUX_HEADER */
tcpip_input();
#if SICSLOWPAN_CONF_FRAG
}
#endif /* SICSLOWPAN_CONF_FRAG */
}
/** @} */
/*--------------------------------------------------------------------*/
/* \brief 6lowpan init function (called by the MAC layer) */
/*--------------------------------------------------------------------*/
void
sicslowpan_init(void)
{
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPHC
/* Preinitialize any address contexts for better header compression
* (Saves up to 13 bytes per 6lowpan packet)
* The platform contiki-conf.h file can override this using e.g.
* #define SICSLOWPAN_CONF_ADDR_CONTEXT_0 {addr_contexts[0].prefix[0]=0xbb;addr_contexts[0].prefix[1]=0xbb;}
*/
#if SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 0
addr_contexts[0].used = 1;
addr_contexts[0].number = 0;
#ifdef SICSLOWPAN_CONF_ADDR_CONTEXT_0
SICSLOWPAN_CONF_ADDR_CONTEXT_0;
#else
addr_contexts[0].prefix[0] = UIP_DS6_DEFAULT_PREFIX_0;
addr_contexts[0].prefix[1] = UIP_DS6_DEFAULT_PREFIX_1;
#endif
#endif /* SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 0 */
#if SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 1
{
int i;
for(i = 1; i < SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS; i++) {
#ifdef SICSLOWPAN_CONF_ADDR_CONTEXT_1
if (i==1) {
addr_contexts[1].used = 1;
addr_contexts[1].number = 1;
SICSLOWPAN_CONF_ADDR_CONTEXT_1;
#ifdef SICSLOWPAN_CONF_ADDR_CONTEXT_2
} else if (i==2) {
addr_contexts[2].used = 1;
addr_contexts[2].number = 2;
SICSLOWPAN_CONF_ADDR_CONTEXT_2;
#endif
} else {
addr_contexts[i].used = 0;
}
#else
addr_contexts[i].used = 0;
#endif /* SICSLOWPAN_CONF_ADDR_CONTEXT_1 */
}
}
#endif /* SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS > 1 */
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPHC */
}
/*--------------------------------------------------------------------*/
int
sicslowpan_get_last_rssi(void)
{
return last_rssi;
}
/*--------------------------------------------------------------------*/
const struct network_driver sicslowpan_driver = {
"sicslowpan",
sicslowpan_init,
input,
output
};
/*--------------------------------------------------------------------*/
/** @} */
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