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osd-contiki/core/net/ipv6/sicslowpan.c

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/**
* \addtogroup sicslowpan
* @{
*/
/*
* 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>
*/
/**
* 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/ip/tcpip.h"
#include "net/ip/uip.h"
#include "net/ipv6/uip-ds6.h"
#include "net/rime/rime.h"
#include "net/ipv6/sicslowpan.h"
#include "net/netstack.h"
#if UIP_CONF_IPV6
#include <stdio.h>
#define DEBUG DEBUG_NONE
#include "net/ip/uip-debug.h"
#if DEBUG
/* PRINTFI and PRINTFO are defined for input and output to debug one without changing the timing of the other */
uint8_t p;
#include <stdio.h>
#define PRINTFI(...) PRINTF(__VA_ARGS__)
#define PRINTFO(...) PRINTF(__VA_ARGS__)
#define PRINTPACKETBUF() PRINTF("packetbuf buffer: "); for(p = 0; p < packetbuf_datalen(); p++){PRINTF("%.2X", *(packetbuf_ptr + p));} PRINTF("\n")
#define PRINTUIPBUF() PRINTF("UIP buffer: "); for(p = 0; p < uip_len; p++){PRINTF("%.2X", uip_buf[p]);}PRINTF("\n")
#define PRINTSICSLOWPANBUF() PRINTF("SICSLOWPAN buffer: "); for(p = 0; p < sicslowpan_len; p++){PRINTF("%.2X", sicslowpan_buf[p]);}PRINTF("\n")
#else
#define PRINTFI(...)
#define PRINTFO(...)
#define PRINTPACKETBUF()
#define PRINTUIPBUF()
#define PRINTSICSLOWPANBUF()
#endif /* DEBUG == 1*/
#if UIP_LOGGING
#include <stdio.h>
void uip_log(char *msg);
#define UIP_LOG(m) uip_log(m)
#else
#define UIP_LOG(m)
#endif /* UIP_LOGGING == 1 */
#ifdef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_MAX_MAC_TRANSMISSIONS SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#else
#define SICSLOWPAN_MAX_MAC_TRANSMISSIONS 4
#endif
#ifndef SICSLOWPAN_COMPRESSION
#ifdef SICSLOWPAN_CONF_COMPRESSION
#define SICSLOWPAN_COMPRESSION SICSLOWPAN_CONF_COMPRESSION
#else
#define SICSLOWPAN_COMPRESSION SICSLOWPAN_COMPRESSION_IPV6
#endif /* SICSLOWPAN_CONF_COMPRESSION */
#endif /* SICSLOWPAN_COMPRESSION */
#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_HC1_PTR (packetbuf_ptr + packetbuf_hdr_len)
#define PACKETBUF_HC1_DISPATCH 0 /* 8 bit */
#define PACKETBUF_HC1_ENCODING 1 /* 8 bit */
#define PACKETBUF_HC1_TTL 2 /* 8 bit */
#define PACKETBUF_HC1_HC_UDP_PTR (packetbuf_ptr + packetbuf_hdr_len)
#define PACKETBUF_HC1_HC_UDP_DISPATCH 0 /* 8 bit */
#define PACKETBUF_HC1_HC_UDP_HC1_ENCODING 1 /* 8 bit */
#define PACKETBUF_HC1_HC_UDP_UDP_ENCODING 2 /* 8 bit */
#define PACKETBUF_HC1_HC_UDP_TTL 3 /* 8 bit */
#define PACKETBUF_HC1_HC_UDP_PORTS 4 /* 8 bit */
#define PACKETBUF_HC1_HC_UDP_CHKSUM 5 /* 16 bit */
/** \name Pointers in the sicslowpan and uip buffer
* @{
*/
#define SICSLOWPAN_IP_BUF ((struct uip_ip_hdr *)&sicslowpan_buf[UIP_LLH_LEN])
#define SICSLOWPAN_UDP_BUF ((struct uip_udp_hdr *)&sicslowpan_buf[UIP_LLIPH_LEN])
#define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
#define UIP_UDP_BUF ((struct uip_udp_hdr *)&uip_buf[UIP_LLIPH_LEN])
#define UIP_TCP_BUF ((struct uip_tcp_hdr *)&uip_buf[UIP_LLIPH_LEN])
#define UIP_ICMP_BUF ((struct uip_icmp_hdr *)&uip_buf[UIP_LLIPH_LEN])
/** @} */
/** \brief Maximum available size for frame headers,
link layer security-related overhead, as well as
6LoWPAN payload. */
#ifdef SICSLOWPAN_CONF_MAC_MAX_PAYLOAD
#define MAC_MAX_PAYLOAD SICSLOWPAN_CONF_MAC_MAX_PAYLOAD
#else /* SICSLOWPAN_CONF_MAC_MAX_PAYLOAD */
#define MAC_MAX_PAYLOAD (127 - 2)
#endif /* SICSLOWPAN_CONF_MAC_MAX_PAYLOAD */
/** \brief Some MAC layers need a minimum payload, which is
configurable through the SICSLOWPAN_CONF_MIN_MAC_PAYLOAD
option. */
#ifdef SICSLOWPAN_CONF_COMPRESSION_THRESHOLD
#define COMPRESSION_THRESHOLD SICSLOWPAN_CONF_COMPRESSION_THRESHOLD
#else
#define COMPRESSION_THRESHOLD 0
#endif
/** \name General variables
* @{
*/
#ifdef SICSLOWPAN_NH_COMPRESSOR
/** A pointer to the additional compressor */
extern struct sicslowpan_nh_compressor SICSLOWPAN_NH_COMPRESSOR;
#endif
/**
* 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;
/**
* the result of the last transmitted fragment
*/
static int last_tx_status;
/** @} */
#if SICSLOWPAN_CONF_FRAG
/** \name Fragmentation related variables
* @{
*/
static uint16_t sicslowpan_len;
/**
* The buffer used for the 6lowpan reassembly.
* This buffer contains only the IPv6 packet (no MAC header, 6lowpan, etc).
* It has a fix size as we do not use dynamic memory allocation.
*/
static uip_buf_t sicslowpan_aligned_buf;
#define sicslowpan_buf (sicslowpan_aligned_buf.u8)
/** The total length of the IPv6 packet in the sicslowpan_buf. */
/**
* length of the ip packet already sent / received.
* It includes IP and transport headers.
*/
static uint16_t processed_ip_in_len;
/** Datagram tag to be put in the fragments I send. */
static uint16_t my_tag;
/** When reassembling, the tag in the fragments being merged. */
static uint16_t reass_tag;
/** When reassembling, the source address of the fragments being merged */
linkaddr_t frag_sender;
/** Reassembly %process %timer. */
static struct timer reass_timer;
/** @} */
#else /* SICSLOWPAN_CONF_FRAG */
/** The buffer used for the 6lowpan processing is uip_buf.
We do not use any additional buffer.*/
#define sicslowpan_buf uip_buf
#define sicslowpan_len uip_len
#endif /* SICSLOWPAN_CONF_FRAG */
static int last_rssi;
/*-------------------------------------------------------------------------*/
/* Rime Sniffer support for one single listener to enable powertrace of IP */
/*-------------------------------------------------------------------------*/
static struct rime_sniffer *callback = NULL;
void
rime_sniffer_add(struct rime_sniffer *s)
{
callback = s;
}
void
rime_sniffer_remove(struct rime_sniffer *s)
{
callback = NULL;
}
static void
set_packet_attrs()
{
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->srcport;
if(UIP_UDP_BUF->destport < c) {
c = UIP_UDP_BUF->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_HC06
/** \name HC06 specific variables
* @{
*/
/** 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 HC06 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;
PRINTF("Uncompressing %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);
}
PRINT6ADDR(ipaddr);
PRINTF("\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.
*
*
* HC-06 (draft-ietf-6lowpan-hc, version 6)\n
* http://tools.ietf.org/html/draft-ietf-6lowpan-hc-06
*
* \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
*/
static void
compress_hdr_hc06(linkaddr_t *link_destaddr)
{
uint8_t tmp, iphc0, iphc1;
#if DEBUG
{ uint16_t ndx;
PRINTF("before compression (%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];
PRINTF("%02x", data);
}
PRINTF("\n");
}
#endif
hc06_ptr = packetbuf_ptr + 2;
/*
* 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 */
PRINTF("IPHC: compressing 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
*/
/* hc06 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 if UDP */
#if UIP_CONF_UDP || UIP_CONF_ROUTER
if(UIP_IP_BUF->proto == UIP_PROTO_UDP) {
iphc0 |= SICSLOWPAN_IPHC_NH_C;
}
#endif /*UIP_CONF_UDP*/
#ifdef SICSLOWPAN_NH_COMPRESSOR
if(SICSLOWPAN_NH_COMPRESSOR.is_compressable(UIP_IP_BUF->proto)) {
iphc0 |= SICSLOWPAN_IPHC_NH_C;
}
#endif
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)) {
PRINTF("IPHC: compressing 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 */
PRINTF("IPHC: compressing 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_link_local(&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_link_local(&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;
#if UIP_CONF_UDP || UIP_CONF_ROUTER
/* UDP header compression */
if(UIP_IP_BUF->proto == UIP_PROTO_UDP) {
PRINTF("IPHC: Uncompressed UDP ports on send side: %x, %x\n",
UIP_HTONS(UIP_UDP_BUF->srcport), UIP_HTONS(UIP_UDP_BUF->destport));
/* Mask out the last 4 bits can be used as a mask */
if(((UIP_HTONS(UIP_UDP_BUF->srcport) & 0xfff0) == SICSLOWPAN_UDP_4_BIT_PORT_MIN) &&
((UIP_HTONS(UIP_UDP_BUF->destport) & 0xfff0) == SICSLOWPAN_UDP_4_BIT_PORT_MIN)) {
/* we can compress 12 bits of both source and dest */
*hc06_ptr = SICSLOWPAN_NHC_UDP_CS_P_11;
PRINTF("IPHC: remove 12 b of both source & dest with prefix 0xFOB\n");
*(hc06_ptr + 1) =
(uint8_t)((UIP_HTONS(UIP_UDP_BUF->srcport) -
SICSLOWPAN_UDP_4_BIT_PORT_MIN) << 4) +
(uint8_t)((UIP_HTONS(UIP_UDP_BUF->destport) -
SICSLOWPAN_UDP_4_BIT_PORT_MIN));
hc06_ptr += 2;
} else if((UIP_HTONS(UIP_UDP_BUF->destport) & 0xff00) == SICSLOWPAN_UDP_8_BIT_PORT_MIN) {
/* we can compress 8 bits of dest, leave source. */
*hc06_ptr = SICSLOWPAN_NHC_UDP_CS_P_01;
PRINTF("IPHC: leave source, remove 8 bits of dest with prefix 0xF0\n");
memcpy(hc06_ptr + 1, &UIP_UDP_BUF->srcport, 2);
*(hc06_ptr + 3) =
(uint8_t)((UIP_HTONS(UIP_UDP_BUF->destport) -
SICSLOWPAN_UDP_8_BIT_PORT_MIN));
hc06_ptr += 4;
} else if((UIP_HTONS(UIP_UDP_BUF->srcport) & 0xff00) == SICSLOWPAN_UDP_8_BIT_PORT_MIN) {
/* we can compress 8 bits of src, leave dest. Copy compressed port */
*hc06_ptr = SICSLOWPAN_NHC_UDP_CS_P_10;
PRINTF("IPHC: remove 8 bits of source with prefix 0xF0, leave dest. hch: %i\n", *hc06_ptr);
*(hc06_ptr + 1) =
(uint8_t)((UIP_HTONS(UIP_UDP_BUF->srcport) -
SICSLOWPAN_UDP_8_BIT_PORT_MIN));
memcpy(hc06_ptr + 2, &UIP_UDP_BUF->destport, 2);
hc06_ptr += 4;
} else {
/* we cannot compress. Copy uncompressed ports, full checksum */
*hc06_ptr = SICSLOWPAN_NHC_UDP_CS_P_00;
PRINTF("IPHC: cannot compress headers\n");
memcpy(hc06_ptr + 1, &UIP_UDP_BUF->srcport, 4);
hc06_ptr += 5;
}
/* always inline the checksum */
if(1) {
memcpy(hc06_ptr, &UIP_UDP_BUF->udpchksum, 2);
hc06_ptr += 2;
}
uncomp_hdr_len += UIP_UDPH_LEN;
}
#endif /*UIP_CONF_UDP*/
#ifdef SICSLOWPAN_NH_COMPRESSOR
/* if nothing to compress just return zero */
hc06_ptr += SICSLOWPAN_NH_COMPRESSOR.compress(hc06_ptr, &uncomp_hdr_len);
#endif
/* before the packetbuf_hdr_len operation */
PACKETBUF_IPHC_BUF[0] = iphc0;
PACKETBUF_IPHC_BUF[1] = iphc1;
packetbuf_hdr_len = hc06_ptr - packetbuf_ptr;
return;
}
/*--------------------------------------------------------------------*/
/**
* \brief Uncompress HC06 (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
* HC06.
* 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 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_hc06(uint16_t ip_len)
{
uint8_t tmp, iphc0, iphc1;
/* 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) {
PRINTF("IPHC: 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->tcflow, hc06_ptr + 1, 3);
tmp = *hc06_ptr;
hc06_ptr += 4;
/* hc06 format of tc is ECN | DSCP , original is DSCP | ECN */
/* set version, pick highest DSCP bits and set in vtc */
SICSLOWPAN_IP_BUF->vtc = 0x60 | ((tmp >> 2) & 0x0f);
/* ECN rolled down two steps + lowest DSCP bits at top two bits */
SICSLOWPAN_IP_BUF->tcflow = ((tmp >> 2) & 0x30) | (tmp << 6) |
(SICSLOWPAN_IP_BUF->tcflow & 0x0f);
} else {
/* Traffic class is compressed (set version and no TC)*/
SICSLOWPAN_IP_BUF->vtc = 0x60;
/* highest flow label bits + ECN bits */
SICSLOWPAN_IP_BUF->tcflow = (*hc06_ptr & 0x0F) |
((*hc06_ptr >> 2) & 0x30);
memcpy(&SICSLOWPAN_IP_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->vtc = 0x60 | ((*hc06_ptr >> 2) & 0x0f);
SICSLOWPAN_IP_BUF->tcflow = ((*hc06_ptr << 6) & 0xC0) | ((*hc06_ptr >> 2) & 0x30);
SICSLOWPAN_IP_BUF->flow = 0;
hc06_ptr += 1;
} else {
/* Traffic class is compressed */
SICSLOWPAN_IP_BUF->vtc = 0x60;
SICSLOWPAN_IP_BUF->tcflow = 0;
SICSLOWPAN_IP_BUF->flow = 0;
}
}
/* Next Header */
if((iphc0 & SICSLOWPAN_IPHC_NH_C) == 0) {
/* Next header is carried inline */
SICSLOWPAN_IP_BUF->proto = *hc06_ptr;
PRINTF("IPHC: next header inline: %d\n", SICSLOWPAN_IP_BUF->proto);
hc06_ptr += 1;
}
/* Hop limit */
if((iphc0 & 0x03) != SICSLOWPAN_IPHC_TTL_I) {
SICSLOWPAN_IP_BUF->ttl = ttl_values[iphc0 & 0x03];
} else {
SICSLOWPAN_IP_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) {
PRINTF("sicslowpan uncompress_hdr: error context not found\n");
return;
}
}
/* if tmp == 0 we do not have a context and therefore no prefix */
uncompress_addr(&SICSLOWPAN_IP_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->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->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) {
PRINTF("sicslowpan uncompress_hdr: error context not found\n");
return;
}
uncompress_addr(&SICSLOWPAN_IP_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->destipaddr, llprefix,
unc_llconf[tmp],
(uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_RECEIVER));
}
}
uncomp_hdr_len += UIP_IPH_LEN;
/* Next header processing - continued */
if((iphc0 & SICSLOWPAN_IPHC_NH_C)) {
/* The next header is compressed, NHC is following */
if((*hc06_ptr & SICSLOWPAN_NHC_UDP_MASK) == SICSLOWPAN_NHC_UDP_ID) {
uint8_t checksum_compressed;
SICSLOWPAN_IP_BUF->proto = UIP_PROTO_UDP;
checksum_compressed = *hc06_ptr & SICSLOWPAN_NHC_UDP_CHECKSUMC;
PRINTF("IPHC: 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(&SICSLOWPAN_UDP_BUF->srcport, hc06_ptr + 1, 2);
memcpy(&SICSLOWPAN_UDP_BUF->destport, hc06_ptr + 3, 2);
PRINTF("IPHC: Uncompressed UDP ports (ptr+5): %x, %x\n",
UIP_HTONS(SICSLOWPAN_UDP_BUF->srcport), UIP_HTONS(SICSLOWPAN_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 */
PRINTF("IPHC: Decompressing destination\n");
memcpy(&SICSLOWPAN_UDP_BUF->srcport, hc06_ptr + 1, 2);
SICSLOWPAN_UDP_BUF->destport = UIP_HTONS(SICSLOWPAN_UDP_8_BIT_PORT_MIN + (*(hc06_ptr + 3)));
PRINTF("IPHC: Uncompressed UDP ports (ptr+4): %x, %x\n",
UIP_HTONS(SICSLOWPAN_UDP_BUF->srcport), UIP_HTONS(SICSLOWPAN_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*/
PRINTF("IPHC: Decompressing source\n");
SICSLOWPAN_UDP_BUF->srcport = UIP_HTONS(SICSLOWPAN_UDP_8_BIT_PORT_MIN +
(*(hc06_ptr + 1)));
memcpy(&SICSLOWPAN_UDP_BUF->destport, hc06_ptr + 2, 2);
PRINTF("IPHC: Uncompressed UDP ports (ptr+4): %x, %x\n",
UIP_HTONS(SICSLOWPAN_UDP_BUF->srcport), UIP_HTONS(SICSLOWPAN_UDP_BUF->destport));
hc06_ptr += 4;
break;
case SICSLOWPAN_NHC_UDP_CS_P_11:
/* 1 byte for NHC, 1 byte for ports */
SICSLOWPAN_UDP_BUF->srcport = UIP_HTONS(SICSLOWPAN_UDP_4_BIT_PORT_MIN +
(*(hc06_ptr + 1) >> 4));
SICSLOWPAN_UDP_BUF->destport = UIP_HTONS(SICSLOWPAN_UDP_4_BIT_PORT_MIN +
((*(hc06_ptr + 1)) & 0x0F));
PRINTF("IPHC: Uncompressed UDP ports (ptr+2): %x, %x\n",
UIP_HTONS(SICSLOWPAN_UDP_BUF->srcport), UIP_HTONS(SICSLOWPAN_UDP_BUF->destport));
hc06_ptr += 2;
break;
default:
PRINTF("sicslowpan uncompress_hdr: error unsupported UDP compression\n");
return;
}
if(!checksum_compressed) { /* has_checksum, default */
memcpy(&SICSLOWPAN_UDP_BUF->udpchksum, hc06_ptr, 2);
hc06_ptr += 2;
PRINTF("IPHC: sicslowpan uncompress_hdr: checksum included\n");
} else {
PRINTF("IPHC: sicslowpan uncompress_hdr: checksum *NOT* included\n");
}
uncomp_hdr_len += UIP_UDPH_LEN;
}
#ifdef SICSLOWPAN_NH_COMPRESSOR
else {
hc06_ptr += SICSLOWPAN_NH_COMPRESSOR.uncompress(hc06_ptr, sicslowpan_buf, &uncomp_hdr_len);
}
#endif
}
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;
/* This is not a fragmented packet */
SICSLOWPAN_IP_BUF->len[0] = len >> 8;
SICSLOWPAN_IP_BUF->len[1] = len & 0x00FF;
} else {
/* This is a 1st fragment */
SICSLOWPAN_IP_BUF->len[0] = (ip_len - UIP_IPH_LEN) >> 8;
SICSLOWPAN_IP_BUF->len[1] = (ip_len - UIP_IPH_LEN) & 0x00FF;
}
/* length field in UDP header */
if(SICSLOWPAN_IP_BUF->proto == UIP_PROTO_UDP) {
memcpy(&SICSLOWPAN_UDP_BUF->udplen, &SICSLOWPAN_IP_BUF->len[0], 2);
}
return;
}
/** @} */
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC06 */
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC1
/*--------------------------------------------------------------------*/
/** \name HC1 compression and uncompression functions
* @{ */
/*--------------------------------------------------------------------*/
/**
* \brief Compress IP/UDP header using HC1 and HC_UDP
*
* 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.
*
*
* If we can compress everything, we use HC1 dispatch, if not we use
* IPv6 dispatch.\n
* We can compress everything if:
* - IP version is
* - Flow label and traffic class are 0
* - Both src and dest ip addresses are link local
* - Both src and dest interface ID are recoverable from lower layer
* header
* - Next header is either ICMP, UDP or TCP
* Moreover, if next header is UDP, we try to compress it using HC_UDP.
* This is feasible is both ports are between F0B0 and F0B0 + 15\n\n
*
* Resulting header structure:
* - For ICMP, TCP, non compressed UDP\n
* HC1 encoding = 11111010 (UDP) 11111110 (TCP) 11111100 (ICMP)\n
* \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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | LoWPAN HC1 Dsp | HC1 encoding | IPv6 Hop limit| L4 hdr + data|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* \endverbatim
*
* - For compressed UDP
* HC1 encoding = 11111011, HC_UDP encoding = 11100000\n
* \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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | LoWPAN HC1 Dsp| HC1 encoding | HC_UDP encod.| IPv6 Hop limit|
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | src p.| dst p.| UDP checksum | L4 data...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* \endverbatim
*
* \param link_destaddr L2 destination address, needed to compress the
* IP destination field
*/
static void
compress_hdr_hc1(linkaddr_t *link_destaddr)
{
/*
* Check if all the assumptions for full compression
* are valid :
*/
if(UIP_IP_BUF->vtc != 0x60 ||
UIP_IP_BUF->tcflow != 0 ||
UIP_IP_BUF->flow != 0 ||
!uip_is_addr_link_local(&UIP_IP_BUF->srcipaddr) ||
!uip_is_addr_mac_addr_based(&UIP_IP_BUF->srcipaddr, &uip_lladdr) ||
!uip_is_addr_link_local(&UIP_IP_BUF->destipaddr) ||
!uip_is_addr_mac_addr_based(&UIP_IP_BUF->destipaddr,
(uip_lladdr_t *)link_destaddr) ||
(UIP_IP_BUF->proto != UIP_PROTO_ICMP6 &&
UIP_IP_BUF->proto != UIP_PROTO_UDP &&
UIP_IP_BUF->proto != UIP_PROTO_TCP))
{
/*
* IPV6 DISPATCH
* Something cannot be compressed, use IPV6 DISPATCH,
* compress nothing, copy IPv6 header in packetbuf buffer
*/
*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;
} else {
/*
* HC1 DISPATCH
* maximum compresssion:
* All fields in the IP header but Hop Limit are elided
* If next header is UDP, we compress UDP header using HC2
*/
PACKETBUF_HC1_PTR[PACKETBUF_HC1_DISPATCH] = SICSLOWPAN_DISPATCH_HC1;
uncomp_hdr_len += UIP_IPH_LEN;
switch(UIP_IP_BUF->proto) {
case UIP_PROTO_ICMP6:
/* HC1 encoding and ttl */
PACKETBUF_HC1_PTR[PACKETBUF_HC1_ENCODING] = 0xFC;
PACKETBUF_HC1_PTR[PACKETBUF_HC1_TTL] = UIP_IP_BUF->ttl;
packetbuf_hdr_len += SICSLOWPAN_HC1_HDR_LEN;
break;
#if UIP_CONF_TCP
case UIP_PROTO_TCP:
/* HC1 encoding and ttl */
PACKETBUF_HC1_PTR[PACKETBUF_HC1_ENCODING] = 0xFE;
PACKETBUF_HC1_PTR[PACKETBUF_HC1_TTL] = UIP_IP_BUF->ttl;
packetbuf_hdr_len += SICSLOWPAN_HC1_HDR_LEN;
break;
#endif /* UIP_CONF_TCP */
#if UIP_CONF_UDP
case UIP_PROTO_UDP:
/*
* try to compress UDP header (we do only full compression).
* This is feasible if both src and dest ports are between
* SICSLOWPAN_UDP_PORT_MIN and SICSLOWPAN_UDP_PORT_MIN + 15
*/
PRINTF("local/remote port %u/%u\n",UIP_UDP_BUF->srcport,UIP_UDP_BUF->destport);
if(UIP_HTONS(UIP_UDP_BUF->srcport) >= SICSLOWPAN_UDP_PORT_MIN &&
UIP_HTONS(UIP_UDP_BUF->srcport) < SICSLOWPAN_UDP_PORT_MAX &&
UIP_HTONS(UIP_UDP_BUF->destport) >= SICSLOWPAN_UDP_PORT_MIN &&
UIP_HTONS(UIP_UDP_BUF->destport) < SICSLOWPAN_UDP_PORT_MAX) {
/* HC1 encoding */
PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_HC1_ENCODING] = 0xFB;
/* HC_UDP encoding, ttl, src and dest ports, checksum */
PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_UDP_ENCODING] = 0xE0;
PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_TTL] = UIP_IP_BUF->ttl;
PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_PORTS] =
(uint8_t)((UIP_HTONS(UIP_UDP_BUF->srcport) -
SICSLOWPAN_UDP_PORT_MIN) << 4) +
(uint8_t)((UIP_HTONS(UIP_UDP_BUF->destport) - SICSLOWPAN_UDP_PORT_MIN));
memcpy(&PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_CHKSUM], &UIP_UDP_BUF->udpchksum, 2);
packetbuf_hdr_len += SICSLOWPAN_HC1_HC_UDP_HDR_LEN;
uncomp_hdr_len += UIP_UDPH_LEN;
} else {
/* HC1 encoding and ttl */
PACKETBUF_HC1_PTR[PACKETBUF_HC1_ENCODING] = 0xFA;
PACKETBUF_HC1_PTR[PACKETBUF_HC1_TTL] = UIP_IP_BUF->ttl;
packetbuf_hdr_len += SICSLOWPAN_HC1_HDR_LEN;
}
break;
#endif /*UIP_CONF_UDP*/
}
}
return;
}
/*--------------------------------------------------------------------*/
/**
* \brief Uncompress HC1 (and HC_UDP) headers and put them in
* sicslowpan_buf
*
* This function is called by the input function when the dispatch is
* HC1.
* 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 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_hc1(uint16_t ip_len)
{
/* version, traffic class, flow label */
SICSLOWPAN_IP_BUF->vtc = 0x60;
SICSLOWPAN_IP_BUF->tcflow = 0;
SICSLOWPAN_IP_BUF->flow = 0;
/* src and dest ip addresses */
uip_ip6addr(&SICSLOWPAN_IP_BUF->srcipaddr, 0xfe80, 0, 0, 0, 0, 0, 0, 0);
uip_ds6_set_addr_iid(&SICSLOWPAN_IP_BUF->srcipaddr,
(uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
uip_ip6addr(&SICSLOWPAN_IP_BUF->destipaddr, 0xfe80, 0, 0, 0, 0, 0, 0, 0);
uip_ds6_set_addr_iid(&SICSLOWPAN_IP_BUF->destipaddr,
(uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_RECEIVER));
uncomp_hdr_len += UIP_IPH_LEN;
/* Next header field */
switch(PACKETBUF_HC1_PTR[PACKETBUF_HC1_ENCODING] & 0x06) {
case SICSLOWPAN_HC1_NH_ICMP6:
SICSLOWPAN_IP_BUF->proto = UIP_PROTO_ICMP6;
SICSLOWPAN_IP_BUF->ttl = PACKETBUF_HC1_PTR[PACKETBUF_HC1_TTL];
packetbuf_hdr_len += SICSLOWPAN_HC1_HDR_LEN;
break;
#if UIP_CONF_TCP
case SICSLOWPAN_HC1_NH_TCP:
SICSLOWPAN_IP_BUF->proto = UIP_PROTO_TCP;
SICSLOWPAN_IP_BUF->ttl = PACKETBUF_HC1_PTR[PACKETBUF_HC1_TTL];
packetbuf_hdr_len += SICSLOWPAN_HC1_HDR_LEN;
break;
#endif/* UIP_CONF_TCP */
#if UIP_CONF_UDP
case SICSLOWPAN_HC1_NH_UDP:
SICSLOWPAN_IP_BUF->proto = UIP_PROTO_UDP;
if(PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_HC1_ENCODING] & 0x01) {
/* UDP header is compressed with HC_UDP */
if(PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_UDP_ENCODING] !=
SICSLOWPAN_HC_UDP_ALL_C) {
PRINTF("sicslowpan (uncompress_hdr), packet not supported");
return;
}
/* IP TTL */
SICSLOWPAN_IP_BUF->ttl = PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_TTL];
/* UDP ports, len, checksum */
SICSLOWPAN_UDP_BUF->srcport =
UIP_HTONS(SICSLOWPAN_UDP_PORT_MIN +
(PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_PORTS] >> 4));
SICSLOWPAN_UDP_BUF->destport =
UIP_HTONS(SICSLOWPAN_UDP_PORT_MIN +
(PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_PORTS] & 0x0F));
memcpy(&SICSLOWPAN_UDP_BUF->udpchksum, &PACKETBUF_HC1_HC_UDP_PTR[PACKETBUF_HC1_HC_UDP_CHKSUM], 2);
uncomp_hdr_len += UIP_UDPH_LEN;
packetbuf_hdr_len += SICSLOWPAN_HC1_HC_UDP_HDR_LEN;
} else {
packetbuf_hdr_len += SICSLOWPAN_HC1_HDR_LEN;
}
break;
#endif/* UIP_CONF_UDP */
default:
/* this shouldn't happen, drop */
return;
}
/* IP length field. */
if(ip_len == 0) {
int len = packetbuf_datalen() - packetbuf_hdr_len + uncomp_hdr_len - UIP_IPH_LEN;
/* This is not a fragmented packet */
SICSLOWPAN_IP_BUF->len[0] = len >> 8;
SICSLOWPAN_IP_BUF->len[1] = len & 0x00FF;
} else {
/* This is a 1st fragment */
SICSLOWPAN_IP_BUF->len[0] = (ip_len - UIP_IPH_LEN) >> 8;
SICSLOWPAN_IP_BUF->len[1] = (ip_len - UIP_IPH_LEN) & 0x00FF;
}
/* length field in UDP header */
if(SICSLOWPAN_IP_BUF->proto == UIP_PROTO_UDP) {
memcpy(&SICSLOWPAN_UDP_BUF->udplen, &SICSLOWPAN_IP_BUF->len[0], 2);
}
return;
}
/** @} */
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC1 */
/*--------------------------------------------------------------------*/
/** \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
*/
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;
}
/** @} */
/*--------------------------------------------------------------------*/
/** \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)
{
uip_ds6_link_neighbor_callback(status, transmissions);
if(callback != NULL) {
callback->output_callback(status);
}
last_tx_status = status;
}
/*--------------------------------------------------------------------*/
/**
* \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
/* Force acknowledge from sender (test hardware autoacks) */
#if SICSLOWPAN_CONF_ACK_ALL
packetbuf_set_attr(PACKETBUF_ATTR_RELIABLE, 1);
#endif
/* Provide a callback function to receive the result of
a packet transmission. */
NETSTACK_LLSEC.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();
}
/*--------------------------------------------------------------------*/
/** \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 uip_lladdr_t *localdest)
{
int framer_hdrlen;
int max_payload;
/* The MAC address of the destination of the packet */
linkaddr_t dest;
/* Number of bytes processed. */
uint16_t processed_ip_out_len;
/* init */
uncomp_hdr_len = 0;
packetbuf_hdr_len = 0;
/* reset packetbuf buffer */
packetbuf_clear();
packetbuf_ptr = packetbuf_dataptr();
packetbuf_set_attr(PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS,
SICSLOWPAN_MAX_MAC_TRANSMISSIONS);
if(callback) {
/* call the attribution when the callback comes, but set attributes
here ! */
set_packet_attrs();
}
#define TCP_FIN 0x01
#define TCP_ACK 0x10
#define TCP_CTL 0x3f
/* Set stream mode for all TCP packets, except FIN packets. */
if(UIP_IP_BUF->proto == UIP_PROTO_TCP &&
(UIP_TCP_BUF->flags & TCP_FIN) == 0 &&
(UIP_TCP_BUF->flags & TCP_CTL) != TCP_ACK) {
packetbuf_set_attr(PACKETBUF_ATTR_PACKET_TYPE,
PACKETBUF_ATTR_PACKET_TYPE_STREAM);
} else if(UIP_IP_BUF->proto == UIP_PROTO_TCP &&
(UIP_TCP_BUF->flags & TCP_FIN) == TCP_FIN) {
packetbuf_set_attr(PACKETBUF_ATTR_PACKET_TYPE,
PACKETBUF_ATTR_PACKET_TYPE_STREAM_END);
}
/*
* 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, (const linkaddr_t *)localdest);
}
PRINTFO("sicslowpan output: sending packet len %d\n", uip_len);
if(uip_len >= COMPRESSION_THRESHOLD) {
/* Try to compress the headers */
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC1
compress_hdr_hc1(&dest);
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC1 */
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPV6
compress_hdr_ipv6(&dest);
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_IPV6 */
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC06
compress_hdr_hc06(&dest);
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC06 */
} else {
compress_hdr_ipv6(&dest);
}
PRINTFO("sicslowpan output: header of len %d\n", packetbuf_hdr_len);
/* Calculate NETSTACK_FRAMER's header length, that will be added in the NETSTACK_RDC.
* We calculate it here only to make a better decision of whether the outgoing packet
* needs to be fragmented or not. */
#define USE_FRAMER_HDRLEN 1
#if USE_FRAMER_HDRLEN
packetbuf_set_addr(PACKETBUF_ADDR_RECEIVER, &dest);
framer_hdrlen = NETSTACK_FRAMER.length();
if(framer_hdrlen < 0) {
/* Framing failed, we assume the maximum header length */
framer_hdrlen = 21;
}
#else /* USE_FRAMER_HDRLEN */
framer_hdrlen = 21;
#endif /* USE_FRAMER_HDRLEN */
max_payload = MAC_MAX_PAYLOAD - framer_hdrlen - NETSTACK_LLSEC.get_overhead();
if((int)uip_len - (int)uncomp_hdr_len > max_payload - (int)packetbuf_hdr_len) {
#if SICSLOWPAN_CONF_FRAG
struct queuebuf *q;
/*
* 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/HC1/HC06/HC_UDP dispatchs/headers.
* The following fragments contain only the fragn dispatch.
*/
PRINTFO("Fragmentation sending packet len %d\n", uip_len);
/* Create 1st Fragment */
PRINTFO("sicslowpan output: 1rst fragment ");
/* move HC1/HC06/IPv6 header */
memmove(packetbuf_ptr + SICSLOWPAN_FRAG1_HDR_LEN, packetbuf_ptr, packetbuf_hdr_len);
/*
* FRAG1 dispatch + header
* Note that the length is in units of 8 bytes
*/
/* PACKETBUF_FRAG_BUF->dispatch_size = */
/* uip_htons((SICSLOWPAN_DISPATCH_FRAG1 << 8) | uip_len); */
SET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_DISPATCH_SIZE,
((SICSLOWPAN_DISPATCH_FRAG1 << 8) | uip_len));
/* PACKETBUF_FRAG_BUF->tag = uip_htons(my_tag); */
SET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_TAG, my_tag);
my_tag++;
/* Copy payload and send */
packetbuf_hdr_len += SICSLOWPAN_FRAG1_HDR_LEN;
packetbuf_payload_len = (max_payload - packetbuf_hdr_len) & 0xfffffff8;
PRINTFO("(len %d, tag %d)\n", packetbuf_payload_len, my_tag);
memcpy(packetbuf_ptr + packetbuf_hdr_len,
(uint8_t *)UIP_IP_BUF + uncomp_hdr_len, packetbuf_payload_len);
packetbuf_set_datalen(packetbuf_payload_len + packetbuf_hdr_len);
q = queuebuf_new_from_packetbuf();
if(q == NULL) {
PRINTFO("could not allocate queuebuf for first fragment, dropping packet\n");
return 0;
}
send_packet(&dest);
queuebuf_to_packetbuf(q);
queuebuf_free(q);
q = NULL;
/* Check tx result. */
if((last_tx_status == MAC_TX_COLLISION) ||
(last_tx_status == MAC_TX_ERR) ||
(last_tx_status == MAC_TX_ERR_FATAL)) {
PRINTFO("error in fragment tx, dropping subsequent fragments.\n");
return 0;
}
/* set processed_ip_out_len to what we already sent from the IP payload*/
processed_ip_out_len = packetbuf_payload_len + uncomp_hdr_len;
/*
* Create following fragments
* Datagram tag is already in the buffer, we need to set the
* FRAGN dispatch and for each fragment, the offset
*/
packetbuf_hdr_len = SICSLOWPAN_FRAGN_HDR_LEN;
/* PACKETBUF_FRAG_BUF->dispatch_size = */
/* uip_htons((SICSLOWPAN_DISPATCH_FRAGN << 8) | uip_len); */
SET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_DISPATCH_SIZE,
((SICSLOWPAN_DISPATCH_FRAGN << 8) | uip_len));
packetbuf_payload_len = (max_payload - packetbuf_hdr_len) & 0xfffffff8;
while(processed_ip_out_len < uip_len) {
PRINTFO("sicslowpan output: fragment ");
PACKETBUF_FRAG_PTR[PACKETBUF_FRAG_OFFSET] = processed_ip_out_len >> 3;
/* Copy payload and send */
if(uip_len - processed_ip_out_len < packetbuf_payload_len) {
/* last fragment */
packetbuf_payload_len = uip_len - processed_ip_out_len;
}
PRINTFO("(offset %d, len %d, tag %d)\n",
processed_ip_out_len >> 3, packetbuf_payload_len, my_tag);
memcpy(packetbuf_ptr + packetbuf_hdr_len,
(uint8_t *)UIP_IP_BUF + processed_ip_out_len, packetbuf_payload_len);
packetbuf_set_datalen(packetbuf_payload_len + packetbuf_hdr_len);
q = queuebuf_new_from_packetbuf();
if(q == NULL) {
PRINTFO("could not allocate queuebuf, dropping fragment\n");
return 0;
}
send_packet(&dest);
queuebuf_to_packetbuf(q);
queuebuf_free(q);
q = NULL;
processed_ip_out_len += packetbuf_payload_len;
/* Check tx result. */
if((last_tx_status == MAC_TX_COLLISION) ||
(last_tx_status == MAC_TX_ERR) ||
(last_tx_status == MAC_TX_ERR_FATAL)) {
PRINTFO("error in fragment tx, dropping subsequent fragments.\n");
return 0;
}
}
#else /* SICSLOWPAN_CONF_FRAG */
PRINTFO("sicslowpan 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.
* \param r The MAC layer
*
* 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 is_fragment = 0;
#if SICSLOWPAN_CONF_FRAG
/* tag of the fragment */
uint16_t frag_tag = 0;
uint8_t first_fragment = 0, last_fragment = 0;
#endif /*SICSLOWPAN_CONF_FRAG*/
/* 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();
/* 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
/* if reassembly timed out, cancel it */
if(timer_expired(&reass_timer)) {
sicslowpan_len = 0;
processed_ip_in_len = 0;
}
/*
* 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) & 0xf800) >> 8) {
case SICSLOWPAN_DISPATCH_FRAG1:
PRINTFI("sicslowpan input: FRAG1 ");
frag_offset = 0;
/* frag_size = (uip_ntohs(PACKETBUF_FRAG_BUF->dispatch_size) & 0x07ff); */
frag_size = GET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_DISPATCH_SIZE) & 0x07ff;
/* frag_tag = uip_ntohs(PACKETBUF_FRAG_BUF->tag); */
frag_tag = GET16(PACKETBUF_FRAG_PTR, PACKETBUF_FRAG_TAG);
PRINTFI("size %d, tag %d, offset %d)\n",
frag_size, frag_tag, frag_offset);
packetbuf_hdr_len += SICSLOWPAN_FRAG1_HDR_LEN;
/* printf("frag1 %d %d\n", reass_tag, frag_tag);*/
first_fragment = 1;
is_fragment = 1;
break;
case SICSLOWPAN_DISPATCH_FRAGN:
/*
* set offset, tag, size
* Offset is in units of 8 bytes
*/
PRINTFI("sicslowpan input: FRAGN ");
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;
PRINTFI("size %d, tag %d, offset %d)\n",
frag_size, frag_tag, frag_offset);
packetbuf_hdr_len += SICSLOWPAN_FRAGN_HDR_LEN;
/* If this is the last fragment, we may shave off any extrenous
bytes at the end. We must be liberal in what we accept. */
PRINTFI("last_fragment?: processed_ip_in_len %d packetbuf_payload_len %d frag_size %d\n",
processed_ip_in_len, packetbuf_datalen() - packetbuf_hdr_len, frag_size);
if(processed_ip_in_len + packetbuf_datalen() - packetbuf_hdr_len >= frag_size) {
last_fragment = 1;
}
is_fragment = 1;
break;
default:
break;
}
/* We are currently reassembling a packet, but have just received the first
* fragment of another packet. We can either ignore it and hope to receive
* the rest of the under-reassembly packet fragments, or we can discard the
* previous packet altogether, and start reassembling the new packet.
*
* We discard the previous packet, and start reassembling the new packet.
* This lessens the negative impacts of too high SICSLOWPAN_REASS_MAXAGE.
*/
#define PRIORITIZE_NEW_PACKETS 1
#if PRIORITIZE_NEW_PACKETS
if(!is_fragment) {
/* Prioritize non-fragment packets too. */
sicslowpan_len = 0;
processed_ip_in_len = 0;
} else if(processed_ip_in_len > 0 && first_fragment
&& !linkaddr_cmp(&frag_sender, packetbuf_addr(PACKETBUF_ADDR_SENDER))) {
sicslowpan_len = 0;
processed_ip_in_len = 0;
}
#endif /* PRIORITIZE_NEW_PACKETS */
if(processed_ip_in_len > 0) {
/* reassembly is ongoing */
/* printf("frag %d %d\n", reass_tag, frag_tag);*/
if((frag_size > 0 &&
(frag_size != sicslowpan_len ||
reass_tag != frag_tag ||
!linkaddr_cmp(&frag_sender, packetbuf_addr(PACKETBUF_ADDR_SENDER)))) ||
frag_size == 0) {
/*
* the packet is a fragment that does not belong to the packet
* being reassembled or the packet is not a fragment.
*/
PRINTFI("sicslowpan input: Dropping 6lowpan packet that is not a fragment of the packet currently being reassembled\n");
return;
}
} else {
/*
* reassembly is off
* start it if we received a fragment
*/
if((frag_size > 0) && (frag_size <= UIP_BUFSIZE)) {
/* We are currently not reassembling a packet, but have received a packet fragment
* that is not the first one. */
if(is_fragment && !first_fragment) {
return;
}
sicslowpan_len = frag_size;
reass_tag = frag_tag;
timer_set(&reass_timer, SICSLOWPAN_REASS_MAXAGE * CLOCK_SECOND / 16);
PRINTFI("sicslowpan input: INIT FRAGMENTATION (len %d, tag %d)\n",
sicslowpan_len, reass_tag);
linkaddr_copy(&frag_sender, packetbuf_addr(PACKETBUF_ADDR_SENDER));
}
}
if(packetbuf_hdr_len == SICSLOWPAN_FRAGN_HDR_LEN) {
/* this is a FRAGN, skip the header compression dispatch section */
goto copypayload;
}
#endif /* SICSLOWPAN_CONF_FRAG */
/* Process next dispatch and headers */
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC06
if((PACKETBUF_HC1_PTR[PACKETBUF_HC1_DISPATCH] & 0xe0) == SICSLOWPAN_DISPATCH_IPHC) {
PRINTFI("sicslowpan input: IPHC\n");
uncompress_hdr_hc06(frag_size);
} else
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC06 */
switch(PACKETBUF_HC1_PTR[PACKETBUF_HC1_DISPATCH]) {
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC1
case SICSLOWPAN_DISPATCH_HC1:
PRINTFI("sicslowpan input: HC1\n");
uncompress_hdr_hc1(frag_size);
break;
#endif /* SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC1 */
case SICSLOWPAN_DISPATCH_IPV6:
PRINTFI("sicslowpan input: IPV6\n");
packetbuf_hdr_len += SICSLOWPAN_IPV6_HDR_LEN;
/* Put uncompressed IP header in sicslowpan_buf. */
memcpy(SICSLOWPAN_IP_BUF, 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;
break;
default:
/* unknown header */
PRINTFI("sicslowpan input: unknown dispatch: %u\n",
PACKETBUF_HC1_PTR[PACKETBUF_HC1_DISPATCH]);
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) {
PRINTF("SICSLOWPAN: packet dropped due to header > total packet\n");
return;
}
packetbuf_payload_len = packetbuf_datalen() - packetbuf_hdr_len;
/* Sanity-check size of incoming packet to avoid buffer overflow */
{
int req_size = UIP_LLH_LEN + uncomp_hdr_len + (uint16_t)(frag_offset << 3)
+ packetbuf_payload_len;
if(req_size > sizeof(sicslowpan_buf)) {
PRINTF(
"SICSLOWPAN: packet dropped, minimum required SICSLOWPAN_IP_BUF size: %d+%d+%d+%d=%d (current size: %d)\n",
UIP_LLH_LEN, uncomp_hdr_len, (uint16_t)(frag_offset << 3),
packetbuf_payload_len, req_size, sizeof(sicslowpan_buf));
return;
}
}
memcpy((uint8_t *)SICSLOWPAN_IP_BUF + uncomp_hdr_len + (uint16_t)(frag_offset << 3), 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) {
processed_ip_in_len += uncomp_hdr_len;
}
/* For the last fragment, we are OK if there is extrenous bytes at
the end of the packet. */
if(last_fragment != 0) {
processed_ip_in_len = frag_size;
} else {
processed_ip_in_len += packetbuf_payload_len;
}
PRINTF("processed_ip_in_len %d, packetbuf_payload_len %d\n", processed_ip_in_len, packetbuf_payload_len);
} else {
#endif /* SICSLOWPAN_CONF_FRAG */
sicslowpan_len = packetbuf_payload_len + uncomp_hdr_len;
#if SICSLOWPAN_CONF_FRAG
}
/*
* If we have a full IP packet in sicslowpan_buf, deliver it to
* the IP stack
*/
PRINTF("sicslowpan_init processed_ip_in_len %d, sicslowpan_len %d\n",
processed_ip_in_len, sicslowpan_len);
if(processed_ip_in_len == 0 || (processed_ip_in_len == sicslowpan_len)) {
PRINTFI("sicslowpan input: IP packet ready (length %d)\n",
sicslowpan_len);
memcpy((uint8_t *)UIP_IP_BUF, (uint8_t *)SICSLOWPAN_IP_BUF, sicslowpan_len);
uip_len = sicslowpan_len;
sicslowpan_len = 0;
processed_ip_in_len = 0;
#endif /* SICSLOWPAN_CONF_FRAG */
#if DEBUG
{
uint16_t ndx;
PRINTF("after decompression %u:", SICSLOWPAN_IP_BUF->len[1]);
for (ndx = 0; ndx < SICSLOWPAN_IP_BUF->len[1] + 40; ndx++) {
uint8_t data = ((uint8_t *) (SICSLOWPAN_IP_BUF))[ndx];
PRINTF("%02x", data);
}
PRINTF("\n");
}
#endif
/* if callback is set then set attributes and call */
if(callback) {
set_packet_attrs();
callback->input_callback();
}
tcpip_input();
#if SICSLOWPAN_CONF_FRAG
}
#endif /* SICSLOWPAN_CONF_FRAG */
}
/** @} */
/*--------------------------------------------------------------------*/
/* \brief 6lowpan init function (called by the MAC layer) */
/*--------------------------------------------------------------------*/
void
sicslowpan_init(void)
{
/*
* Set out output function as the function to be called from uIP to
* send a packet.
*/
tcpip_set_outputfunc(output);
#if SICSLOWPAN_COMPRESSION == SICSLOWPAN_COMPRESSION_HC06
/* 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] = 0xaa;
addr_contexts[0].prefix[1] = 0xaa;
#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_HC06 */
}
/*--------------------------------------------------------------------*/
int
sicslowpan_get_last_rssi(void)
{
return last_rssi;
}
/*--------------------------------------------------------------------*/
const struct network_driver sicslowpan_driver = {
"sicslowpan",
sicslowpan_init,
input
};
/*--------------------------------------------------------------------*/
/** @} */
#endif /* UIP_CONF_IPV6 */
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