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osd-contiki/core/net/rpl/rpl-icmp6.c
Simon Duquennoy 47ba4c0c4b Implement RPL probing
2015-05-08 14:32:00 +02:00

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/*
* Copyright (c) 2010, 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
* ICMP6 I/O for RPL control messages.
*
* \author Joakim Eriksson <joakime@sics.se>, Nicolas Tsiftes <nvt@sics.se>
* Contributors: Niclas Finne <nfi@sics.se>, Joel Hoglund <joel@sics.se>,
* Mathieu Pouillot <m.pouillot@watteco.com>
* George Oikonomou <oikonomou@users.sourceforge.net> (multicast)
*/
/**
* \addtogroup uip6
* @{
*/
#include "net/ip/tcpip.h"
#include "net/ip/uip.h"
#include "net/ipv6/uip-ds6.h"
#include "net/ipv6/uip-nd6.h"
#include "net/ipv6/uip-icmp6.h"
#include "net/rpl/rpl-private.h"
#include "net/packetbuf.h"
#include "net/ipv6/multicast/uip-mcast6.h"
#include <limits.h>
#include <string.h>
#define DEBUG DEBUG_NONE
#include "net/ip/uip-debug.h"
/*---------------------------------------------------------------------------*/
#define RPL_DIO_GROUNDED 0x80
#define RPL_DIO_MOP_SHIFT 3
#define RPL_DIO_MOP_MASK 0x38
#define RPL_DIO_PREFERENCE_MASK 0x07
#define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
#define UIP_ICMP_BUF ((struct uip_icmp_hdr *)&uip_buf[uip_l2_l3_hdr_len])
#define UIP_ICMP_PAYLOAD ((unsigned char *)&uip_buf[uip_l2_l3_icmp_hdr_len])
/*---------------------------------------------------------------------------*/
static void dis_input(void);
static void dio_input(void);
static void dao_input(void);
static void dao_ack_input(void);
/* some debug callbacks useful when debugging RPL networks */
#ifdef RPL_DEBUG_DIO_INPUT
void RPL_DEBUG_DIO_INPUT(uip_ipaddr_t *, rpl_dio_t *);
#endif
#ifdef RPL_DEBUG_DAO_OUTPUT
void RPL_DEBUG_DAO_OUTPUT(rpl_parent_t *);
#endif
static uint8_t dao_sequence = RPL_LOLLIPOP_INIT;
extern rpl_of_t RPL_OF;
#if RPL_CONF_MULTICAST
static uip_mcast6_route_t *mcast_group;
#endif
/*---------------------------------------------------------------------------*/
/* Initialise RPL ICMPv6 message handlers */
UIP_ICMP6_HANDLER(dis_handler, ICMP6_RPL, RPL_CODE_DIS, dis_input);
UIP_ICMP6_HANDLER(dio_handler, ICMP6_RPL, RPL_CODE_DIO, dio_input);
UIP_ICMP6_HANDLER(dao_handler, ICMP6_RPL, RPL_CODE_DAO, dao_input);
UIP_ICMP6_HANDLER(dao_ack_handler, ICMP6_RPL, RPL_CODE_DAO_ACK, dao_ack_input);
/*---------------------------------------------------------------------------*/
static int
get_global_addr(uip_ipaddr_t *addr)
{
int i;
int state;
for(i = 0; i < UIP_DS6_ADDR_NB; i++) {
state = uip_ds6_if.addr_list[i].state;
if(uip_ds6_if.addr_list[i].isused &&
(state == ADDR_TENTATIVE || state == ADDR_PREFERRED)) {
if(!uip_is_addr_link_local(&uip_ds6_if.addr_list[i].ipaddr)) {
memcpy(addr, &uip_ds6_if.addr_list[i].ipaddr, sizeof(uip_ipaddr_t));
return 1;
}
}
}
return 0;
}
/*---------------------------------------------------------------------------*/
static uint32_t
get32(uint8_t *buffer, int pos)
{
return (uint32_t)buffer[pos] << 24 | (uint32_t)buffer[pos + 1] << 16 |
(uint32_t)buffer[pos + 2] << 8 | buffer[pos + 3];
}
/*---------------------------------------------------------------------------*/
static void
set32(uint8_t *buffer, int pos, uint32_t value)
{
buffer[pos++] = value >> 24;
buffer[pos++] = (value >> 16) & 0xff;
buffer[pos++] = (value >> 8) & 0xff;
buffer[pos++] = value & 0xff;
}
/*---------------------------------------------------------------------------*/
static uint16_t
get16(uint8_t *buffer, int pos)
{
return (uint16_t)buffer[pos] << 8 | buffer[pos + 1];
}
/*---------------------------------------------------------------------------*/
static void
set16(uint8_t *buffer, int pos, uint16_t value)
{
buffer[pos++] = value >> 8;
buffer[pos++] = value & 0xff;
}
/*---------------------------------------------------------------------------*/
static void
dis_input(void)
{
rpl_instance_t *instance;
rpl_instance_t *end;
/* DAG Information Solicitation */
PRINTF("RPL: Received a DIS from ");
PRINT6ADDR(&UIP_IP_BUF->srcipaddr);
PRINTF("\n");
for(instance = &instance_table[0], end = instance + RPL_MAX_INSTANCES;
instance < end; ++instance) {
if(instance->used == 1) {
#if RPL_LEAF_ONLY
if(!uip_is_addr_mcast(&UIP_IP_BUF->destipaddr)) {
PRINTF("RPL: LEAF ONLY Multicast DIS will NOT reset DIO timer\n");
#else /* !RPL_LEAF_ONLY */
if(uip_is_addr_mcast(&UIP_IP_BUF->destipaddr)) {
PRINTF("RPL: Multicast DIS => reset DIO timer\n");
rpl_reset_dio_timer(instance);
} else {
#endif /* !RPL_LEAF_ONLY */
PRINTF("RPL: Unicast DIS, reply to sender\n");
dio_output(instance, &UIP_IP_BUF->srcipaddr);
}
}
}
uip_len = 0;
}
/*---------------------------------------------------------------------------*/
void
dis_output(uip_ipaddr_t *addr)
{
unsigned char *buffer;
uip_ipaddr_t tmpaddr;
/*
* DAG Information Solicitation - 2 bytes reserved
* 0 1 2
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Flags | Reserved | Option(s)...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
buffer = UIP_ICMP_PAYLOAD;
buffer[0] = buffer[1] = 0;
if(addr == NULL) {
uip_create_linklocal_rplnodes_mcast(&tmpaddr);
addr = &tmpaddr;
}
PRINTF("RPL: Sending a DIS to ");
PRINT6ADDR(addr);
PRINTF("\n");
uip_icmp6_send(addr, ICMP6_RPL, RPL_CODE_DIS, 2);
}
/*---------------------------------------------------------------------------*/
static void
dio_input(void)
{
unsigned char *buffer;
uint8_t buffer_length;
rpl_dio_t dio;
uint8_t subopt_type;
int i;
int len;
uip_ipaddr_t from;
uip_ds6_nbr_t *nbr;
memset(&dio, 0, sizeof(dio));
/* Set default values in case the DIO configuration option is missing. */
dio.dag_intdoubl = RPL_DIO_INTERVAL_DOUBLINGS;
dio.dag_intmin = RPL_DIO_INTERVAL_MIN;
dio.dag_redund = RPL_DIO_REDUNDANCY;
dio.dag_min_hoprankinc = RPL_MIN_HOPRANKINC;
dio.dag_max_rankinc = RPL_MAX_RANKINC;
dio.ocp = RPL_OF.ocp;
dio.default_lifetime = RPL_DEFAULT_LIFETIME;
dio.lifetime_unit = RPL_DEFAULT_LIFETIME_UNIT;
uip_ipaddr_copy(&from, &UIP_IP_BUF->srcipaddr);
/* DAG Information Object */
PRINTF("RPL: Received a DIO from ");
PRINT6ADDR(&from);
PRINTF("\n");
if((nbr = uip_ds6_nbr_lookup(&from)) == NULL) {
if((nbr = uip_ds6_nbr_add(&from, (uip_lladdr_t *)
packetbuf_addr(PACKETBUF_ADDR_SENDER),
0, NBR_REACHABLE)) != NULL) {
/* set reachable timer */
stimer_set(&nbr->reachable, UIP_ND6_REACHABLE_TIME / 1000);
PRINTF("RPL: Neighbor added to neighbor cache ");
PRINT6ADDR(&from);
PRINTF(", ");
PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
PRINTF("\n");
} else {
PRINTF("RPL: Out of memory, dropping DIO from ");
PRINT6ADDR(&from);
PRINTF(", ");
PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
PRINTF("\n");
return;
}
} else {
PRINTF("RPL: Neighbor already in neighbor cache\n");
}
buffer_length = uip_len - uip_l3_icmp_hdr_len;
/* Process the DIO base option. */
i = 0;
buffer = UIP_ICMP_PAYLOAD;
dio.instance_id = buffer[i++];
dio.version = buffer[i++];
dio.rank = get16(buffer, i);
i += 2;
PRINTF("RPL: Incoming DIO (id, ver, rank) = (%u,%u,%u)\n",
(unsigned)dio.instance_id,
(unsigned)dio.version,
(unsigned)dio.rank);
dio.grounded = buffer[i] & RPL_DIO_GROUNDED;
dio.mop = (buffer[i]& RPL_DIO_MOP_MASK) >> RPL_DIO_MOP_SHIFT;
dio.preference = buffer[i++] & RPL_DIO_PREFERENCE_MASK;
dio.dtsn = buffer[i++];
/* two reserved bytes */
i += 2;
memcpy(&dio.dag_id, buffer + i, sizeof(dio.dag_id));
i += sizeof(dio.dag_id);
PRINTF("RPL: Incoming DIO (dag_id, pref) = (");
PRINT6ADDR(&dio.dag_id);
PRINTF(", %u)\n", dio.preference);
/* Check if there are any DIO suboptions. */
for(; i < buffer_length; i += len) {
subopt_type = buffer[i];
if(subopt_type == RPL_OPTION_PAD1) {
len = 1;
} else {
/* Suboption with a two-byte header + payload */
len = 2 + buffer[i + 1];
}
if(len + i > buffer_length) {
PRINTF("RPL: Invalid DIO packet\n");
RPL_STAT(rpl_stats.malformed_msgs++);
return;
}
PRINTF("RPL: DIO option %u, length: %u\n", subopt_type, len - 2);
switch(subopt_type) {
case RPL_OPTION_DAG_METRIC_CONTAINER:
if(len < 6) {
PRINTF("RPL: Invalid DAG MC, len = %d\n", len);
RPL_STAT(rpl_stats.malformed_msgs++);
return;
}
dio.mc.type = buffer[i + 2];
dio.mc.flags = buffer[i + 3] << 1;
dio.mc.flags |= buffer[i + 4] >> 7;
dio.mc.aggr = (buffer[i + 4] >> 4) & 0x3;
dio.mc.prec = buffer[i + 4] & 0xf;
dio.mc.length = buffer[i + 5];
if(dio.mc.type == RPL_DAG_MC_NONE) {
/* No metric container: do nothing */
} else if(dio.mc.type == RPL_DAG_MC_ETX) {
dio.mc.obj.etx = get16(buffer, i + 6);
PRINTF("RPL: DAG MC: type %u, flags %u, aggr %u, prec %u, length %u, ETX %u\n",
(unsigned)dio.mc.type,
(unsigned)dio.mc.flags,
(unsigned)dio.mc.aggr,
(unsigned)dio.mc.prec,
(unsigned)dio.mc.length,
(unsigned)dio.mc.obj.etx);
} else if(dio.mc.type == RPL_DAG_MC_ENERGY) {
dio.mc.obj.energy.flags = buffer[i + 6];
dio.mc.obj.energy.energy_est = buffer[i + 7];
} else {
PRINTF("RPL: Unhandled DAG MC type: %u\n", (unsigned)dio.mc.type);
return;
}
break;
case RPL_OPTION_ROUTE_INFO:
if(len < 9) {
PRINTF("RPL: Invalid destination prefix option, len = %d\n", len);
RPL_STAT(rpl_stats.malformed_msgs++);
return;
}
/* The flags field includes the preference value. */
dio.destination_prefix.length = buffer[i + 2];
dio.destination_prefix.flags = buffer[i + 3];
dio.destination_prefix.lifetime = get32(buffer, i + 4);
if(((dio.destination_prefix.length + 7) / 8) + 8 <= len &&
dio.destination_prefix.length <= 128) {
PRINTF("RPL: Copying destination prefix\n");
memcpy(&dio.destination_prefix.prefix, &buffer[i + 8],
(dio.destination_prefix.length + 7) / 8);
} else {
PRINTF("RPL: Invalid route info option, len = %d\n", len);
RPL_STAT(rpl_stats.malformed_msgs++);
return;
}
break;
case RPL_OPTION_DAG_CONF:
if(len != 16) {
PRINTF("RPL: Invalid DAG configuration option, len = %d\n", len);
RPL_STAT(rpl_stats.malformed_msgs++);
return;
}
/* Path control field not yet implemented - at i + 2 */
dio.dag_intdoubl = buffer[i + 3];
dio.dag_intmin = buffer[i + 4];
dio.dag_redund = buffer[i + 5];
dio.dag_max_rankinc = get16(buffer, i + 6);
dio.dag_min_hoprankinc = get16(buffer, i + 8);
dio.ocp = get16(buffer, i + 10);
/* buffer + 12 is reserved */
dio.default_lifetime = buffer[i + 13];
dio.lifetime_unit = get16(buffer, i + 14);
PRINTF("RPL: DAG conf:dbl=%d, min=%d red=%d maxinc=%d mininc=%d ocp=%d d_l=%u l_u=%u\n",
dio.dag_intdoubl, dio.dag_intmin, dio.dag_redund,
dio.dag_max_rankinc, dio.dag_min_hoprankinc, dio.ocp,
dio.default_lifetime, dio.lifetime_unit);
break;
case RPL_OPTION_PREFIX_INFO:
if(len != 32) {
PRINTF("RPL: Invalid DAG prefix info, len != 32\n");
RPL_STAT(rpl_stats.malformed_msgs++);
return;
}
dio.prefix_info.length = buffer[i + 2];
dio.prefix_info.flags = buffer[i + 3];
/* valid lifetime is ingnored for now - at i + 4 */
/* preferred lifetime stored in lifetime */
dio.prefix_info.lifetime = get32(buffer, i + 8);
/* 32-bit reserved at i + 12 */
PRINTF("RPL: Copying prefix information\n");
memcpy(&dio.prefix_info.prefix, &buffer[i + 16], 16);
break;
default:
PRINTF("RPL: Unsupported suboption type in DIO: %u\n",
(unsigned)subopt_type);
}
}
#ifdef RPL_DEBUG_DIO_INPUT
RPL_DEBUG_DIO_INPUT(&from, &dio);
#endif
rpl_process_dio(&from, &dio);
uip_len = 0;
}
/*---------------------------------------------------------------------------*/
void
dio_output(rpl_instance_t *instance, uip_ipaddr_t *uc_addr)
{
unsigned char *buffer;
int pos;
rpl_dag_t *dag = instance->current_dag;
#if !RPL_LEAF_ONLY
uip_ipaddr_t addr;
#endif /* !RPL_LEAF_ONLY */
#if RPL_LEAF_ONLY
/* In leaf mode, we only send DIO messages as unicasts in response to
unicast DIS messages. */
if(uc_addr == NULL) {
PRINTF("RPL: LEAF ONLY have multicast addr: skip dio_output\n");
return;
}
#endif /* RPL_LEAF_ONLY */
/* DAG Information Object */
pos = 0;
buffer = UIP_ICMP_PAYLOAD;
buffer[pos++] = instance->instance_id;
buffer[pos++] = dag->version;
#if RPL_LEAF_ONLY
PRINTF("RPL: LEAF ONLY DIO rank set to INFINITE_RANK\n");
set16(buffer, pos, INFINITE_RANK);
#else /* RPL_LEAF_ONLY */
set16(buffer, pos, dag->rank);
#endif /* RPL_LEAF_ONLY */
pos += 2;
buffer[pos] = 0;
if(dag->grounded) {
buffer[pos] |= RPL_DIO_GROUNDED;
}
buffer[pos] |= instance->mop << RPL_DIO_MOP_SHIFT;
buffer[pos] |= dag->preference & RPL_DIO_PREFERENCE_MASK;
pos++;
buffer[pos++] = instance->dtsn_out;
if(uc_addr == NULL) {
/* Request new DAO to refresh route. We do not do this for unicast DIO
* in order to avoid DAO messages after a DIS-DIO update,
* or upon unicast DIO probing. */
RPL_LOLLIPOP_INCREMENT(instance->dtsn_out);
}
/* reserved 2 bytes */
buffer[pos++] = 0; /* flags */
buffer[pos++] = 0; /* reserved */
memcpy(buffer + pos, &dag->dag_id, sizeof(dag->dag_id));
pos += 16;
#if !RPL_LEAF_ONLY
if(instance->mc.type != RPL_DAG_MC_NONE) {
instance->of->update_metric_container(instance);
buffer[pos++] = RPL_OPTION_DAG_METRIC_CONTAINER;
buffer[pos++] = 6;
buffer[pos++] = instance->mc.type;
buffer[pos++] = instance->mc.flags >> 1;
buffer[pos] = (instance->mc.flags & 1) << 7;
buffer[pos++] |= (instance->mc.aggr << 4) | instance->mc.prec;
if(instance->mc.type == RPL_DAG_MC_ETX) {
buffer[pos++] = 2;
set16(buffer, pos, instance->mc.obj.etx);
pos += 2;
} else if(instance->mc.type == RPL_DAG_MC_ENERGY) {
buffer[pos++] = 2;
buffer[pos++] = instance->mc.obj.energy.flags;
buffer[pos++] = instance->mc.obj.energy.energy_est;
} else {
PRINTF("RPL: Unable to send DIO because of unhandled DAG MC type %u\n",
(unsigned)instance->mc.type);
return;
}
}
#endif /* !RPL_LEAF_ONLY */
/* Always add a DAG configuration option. */
buffer[pos++] = RPL_OPTION_DAG_CONF;
buffer[pos++] = 14;
buffer[pos++] = 0; /* No Auth, PCS = 0 */
buffer[pos++] = instance->dio_intdoubl;
buffer[pos++] = instance->dio_intmin;
buffer[pos++] = instance->dio_redundancy;
set16(buffer, pos, instance->max_rankinc);
pos += 2;
set16(buffer, pos, instance->min_hoprankinc);
pos += 2;
/* OCP is in the DAG_CONF option */
set16(buffer, pos, instance->of->ocp);
pos += 2;
buffer[pos++] = 0; /* reserved */
buffer[pos++] = instance->default_lifetime;
set16(buffer, pos, instance->lifetime_unit);
pos += 2;
/* Check if we have a prefix to send also. */
if(dag->prefix_info.length > 0) {
buffer[pos++] = RPL_OPTION_PREFIX_INFO;
buffer[pos++] = 30; /* always 30 bytes + 2 long */
buffer[pos++] = dag->prefix_info.length;
buffer[pos++] = dag->prefix_info.flags;
set32(buffer, pos, dag->prefix_info.lifetime);
pos += 4;
set32(buffer, pos, dag->prefix_info.lifetime);
pos += 4;
memset(&buffer[pos], 0, 4);
pos += 4;
memcpy(&buffer[pos], &dag->prefix_info.prefix, 16);
pos += 16;
PRINTF("RPL: Sending prefix info in DIO for ");
PRINT6ADDR(&dag->prefix_info.prefix);
PRINTF("\n");
} else {
PRINTF("RPL: No prefix to announce (len %d)\n",
dag->prefix_info.length);
}
#if RPL_LEAF_ONLY
#if (DEBUG) & DEBUG_PRINT
if(uc_addr == NULL) {
PRINTF("RPL: LEAF ONLY sending unicast-DIO from multicast-DIO\n");
}
#endif /* DEBUG_PRINT */
PRINTF("RPL: Sending unicast-DIO with rank %u to ",
(unsigned)dag->rank);
PRINT6ADDR(uc_addr);
PRINTF("\n");
uip_icmp6_send(uc_addr, ICMP6_RPL, RPL_CODE_DIO, pos);
#else /* RPL_LEAF_ONLY */
/* Unicast requests get unicast replies! */
if(uc_addr == NULL) {
PRINTF("RPL: Sending a multicast-DIO with rank %u\n",
(unsigned)instance->current_dag->rank);
uip_create_linklocal_rplnodes_mcast(&addr);
uip_icmp6_send(&addr, ICMP6_RPL, RPL_CODE_DIO, pos);
} else {
PRINTF("RPL: Sending unicast-DIO with rank %u to ",
(unsigned)instance->current_dag->rank);
PRINT6ADDR(uc_addr);
PRINTF("\n");
uip_icmp6_send(uc_addr, ICMP6_RPL, RPL_CODE_DIO, pos);
}
#endif /* RPL_LEAF_ONLY */
}
/*---------------------------------------------------------------------------*/
static void
dao_input(void)
{
uip_ipaddr_t dao_sender_addr;
rpl_dag_t *dag;
rpl_instance_t *instance;
unsigned char *buffer;
uint16_t sequence;
uint8_t instance_id;
uint8_t lifetime;
uint8_t prefixlen;
uint8_t flags;
uint8_t subopt_type;
/*
uint8_t pathcontrol;
uint8_t pathsequence;
*/
uip_ipaddr_t prefix;
uip_ds6_route_t *rep;
uint8_t buffer_length;
int pos;
int len;
int i;
int learned_from;
rpl_parent_t *parent;
uip_ds6_nbr_t *nbr;
prefixlen = 0;
parent = NULL;
uip_ipaddr_copy(&dao_sender_addr, &UIP_IP_BUF->srcipaddr);
/* Destination Advertisement Object */
PRINTF("RPL: Received a DAO from ");
PRINT6ADDR(&dao_sender_addr);
PRINTF("\n");
buffer = UIP_ICMP_PAYLOAD;
buffer_length = uip_len - uip_l3_icmp_hdr_len;
pos = 0;
instance_id = buffer[pos++];
instance = rpl_get_instance(instance_id);
if(instance == NULL) {
PRINTF("RPL: Ignoring a DAO for an unknown RPL instance(%u)\n",
instance_id);
return;
}
lifetime = instance->default_lifetime;
flags = buffer[pos++];
/* reserved */
pos++;
sequence = buffer[pos++];
dag = instance->current_dag;
/* Is the DAG ID present? */
if(flags & RPL_DAO_D_FLAG) {
if(memcmp(&dag->dag_id, &buffer[pos], sizeof(dag->dag_id))) {
PRINTF("RPL: Ignoring a DAO for a DAG different from ours\n");
return;
}
pos += 16;
}
learned_from = uip_is_addr_mcast(&dao_sender_addr) ?
RPL_ROUTE_FROM_MULTICAST_DAO : RPL_ROUTE_FROM_UNICAST_DAO;
PRINTF("RPL: DAO from %s\n",
learned_from == RPL_ROUTE_FROM_UNICAST_DAO? "unicast": "multicast");
if(learned_from == RPL_ROUTE_FROM_UNICAST_DAO) {
/* Check whether this is a DAO forwarding loop. */
parent = rpl_find_parent(dag, &dao_sender_addr);
/* check if this is a new DAO registration with an "illegal" rank */
/* if we already route to this node it is likely */
if(parent != NULL &&
DAG_RANK(parent->rank, instance) < DAG_RANK(dag->rank, instance)) {
PRINTF("RPL: Loop detected when receiving a unicast DAO from a node with a lower rank! (%u < %u)\n",
DAG_RANK(parent->rank, instance), DAG_RANK(dag->rank, instance));
parent->rank = INFINITE_RANK;
parent->flags |= RPL_PARENT_FLAG_UPDATED;
return;
}
/* If we get the DAO from our parent, we also have a loop. */
if(parent != NULL && parent == dag->preferred_parent) {
PRINTF("RPL: Loop detected when receiving a unicast DAO from our parent\n");
parent->rank = INFINITE_RANK;
parent->flags |= RPL_PARENT_FLAG_UPDATED;
return;
}
}
/* Check if there are any RPL options present. */
for(i = pos; i < buffer_length; i += len) {
subopt_type = buffer[i];
if(subopt_type == RPL_OPTION_PAD1) {
len = 1;
} else {
/* The option consists of a two-byte header and a payload. */
len = 2 + buffer[i + 1];
}
switch(subopt_type) {
case RPL_OPTION_TARGET:
/* Handle the target option. */
prefixlen = buffer[i + 3];
memset(&prefix, 0, sizeof(prefix));
memcpy(&prefix, buffer + i + 4, (prefixlen + 7) / CHAR_BIT);
break;
case RPL_OPTION_TRANSIT:
/* The path sequence and control are ignored. */
/* pathcontrol = buffer[i + 3];
pathsequence = buffer[i + 4];*/
lifetime = buffer[i + 5];
/* The parent address is also ignored. */
break;
}
}
PRINTF("RPL: DAO lifetime: %u, prefix length: %u prefix: ",
(unsigned)lifetime, (unsigned)prefixlen);
PRINT6ADDR(&prefix);
PRINTF("\n");
#if RPL_CONF_MULTICAST
if(uip_is_addr_mcast_global(&prefix)) {
mcast_group = uip_mcast6_route_add(&prefix);
if(mcast_group) {
mcast_group->dag = dag;
mcast_group->lifetime = RPL_LIFETIME(instance, lifetime);
}
goto fwd_dao;
}
#endif
rep = uip_ds6_route_lookup(&prefix);
if(lifetime == RPL_ZERO_LIFETIME) {
PRINTF("RPL: No-Path DAO received\n");
/* No-Path DAO received; invoke the route purging routine. */
if(rep != NULL &&
rep->state.nopath_received == 0 &&
rep->length == prefixlen &&
uip_ds6_route_nexthop(rep) != NULL &&
uip_ipaddr_cmp(uip_ds6_route_nexthop(rep), &dao_sender_addr)) {
PRINTF("RPL: Setting expiration timer for prefix ");
PRINT6ADDR(&prefix);
PRINTF("\n");
rep->state.nopath_received = 1;
rep->state.lifetime = DAO_EXPIRATION_TIMEOUT;
/* We forward the incoming no-path DAO to our parent, if we have
one. */
if(dag->preferred_parent != NULL &&
rpl_get_parent_ipaddr(dag->preferred_parent) != NULL) {
PRINTF("RPL: Forwarding no-path DAO to parent ");
PRINT6ADDR(rpl_get_parent_ipaddr(dag->preferred_parent));
PRINTF("\n");
uip_icmp6_send(rpl_get_parent_ipaddr(dag->preferred_parent),
ICMP6_RPL, RPL_CODE_DAO, buffer_length);
}
if(flags & RPL_DAO_K_FLAG) {
dao_ack_output(instance, &dao_sender_addr, sequence);
}
}
return;
}
PRINTF("RPL: adding DAO route\n");
if((nbr = uip_ds6_nbr_lookup(&dao_sender_addr)) == NULL) {
if((nbr = uip_ds6_nbr_add(&dao_sender_addr,
(uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER),
0, NBR_REACHABLE)) != NULL) {
/* set reachable timer */
stimer_set(&nbr->reachable, UIP_ND6_REACHABLE_TIME / 1000);
PRINTF("RPL: Neighbor added to neighbor cache ");
PRINT6ADDR(&dao_sender_addr);
PRINTF(", ");
PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
PRINTF("\n");
} else {
PRINTF("RPL: Out of Memory, dropping DAO from ");
PRINT6ADDR(&dao_sender_addr);
PRINTF(", ");
PRINTLLADDR((uip_lladdr_t *)packetbuf_addr(PACKETBUF_ADDR_SENDER));
PRINTF("\n");
return;
}
} else {
PRINTF("RPL: Neighbor already in neighbor cache\n");
}
rpl_lock_parent(parent);
rep = rpl_add_route(dag, &prefix, prefixlen, &dao_sender_addr);
if(rep == NULL) {
RPL_STAT(rpl_stats.mem_overflows++);
PRINTF("RPL: Could not add a route after receiving a DAO\n");
return;
}
rep->state.lifetime = RPL_LIFETIME(instance, lifetime);
rep->state.learned_from = learned_from;
rep->state.nopath_received = 0;
#if RPL_CONF_MULTICAST
fwd_dao:
#endif
if(learned_from == RPL_ROUTE_FROM_UNICAST_DAO) {
if(dag->preferred_parent != NULL &&
rpl_get_parent_ipaddr(dag->preferred_parent) != NULL) {
PRINTF("RPL: Forwarding DAO to parent ");
PRINT6ADDR(rpl_get_parent_ipaddr(dag->preferred_parent));
PRINTF("\n");
uip_icmp6_send(rpl_get_parent_ipaddr(dag->preferred_parent),
ICMP6_RPL, RPL_CODE_DAO, buffer_length);
}
if(flags & RPL_DAO_K_FLAG) {
dao_ack_output(instance, &dao_sender_addr, sequence);
}
}
uip_len = 0;
}
/*---------------------------------------------------------------------------*/
void
dao_output(rpl_parent_t *parent, uint8_t lifetime)
{
/* Destination Advertisement Object */
uip_ipaddr_t prefix;
if(get_global_addr(&prefix) == 0) {
PRINTF("RPL: No global address set for this node - suppressing DAO\n");
return;
}
/* Sending a DAO with own prefix as target */
dao_output_target(parent, &prefix, lifetime);
}
/*---------------------------------------------------------------------------*/
void
dao_output_target(rpl_parent_t *parent, uip_ipaddr_t *prefix, uint8_t lifetime)
{
rpl_dag_t *dag;
rpl_instance_t *instance;
unsigned char *buffer;
uint8_t prefixlen;
int pos;
/* Destination Advertisement Object */
/* If we are in feather mode, we should not send any DAOs */
if(rpl_get_mode() == RPL_MODE_FEATHER) {
return;
}
if(parent == NULL) {
PRINTF("RPL dao_output_target error parent NULL\n");
return;
}
dag = parent->dag;
if(dag == NULL) {
PRINTF("RPL dao_output_target error dag NULL\n");
return;
}
instance = dag->instance;
if(instance == NULL) {
PRINTF("RPL dao_output_target error instance NULL\n");
return;
}
if(prefix == NULL) {
PRINTF("RPL dao_output_target error prefix NULL\n");
return;
}
#ifdef RPL_DEBUG_DAO_OUTPUT
RPL_DEBUG_DAO_OUTPUT(parent);
#endif
buffer = UIP_ICMP_PAYLOAD;
RPL_LOLLIPOP_INCREMENT(dao_sequence);
pos = 0;
buffer[pos++] = instance->instance_id;
buffer[pos] = 0;
#if RPL_DAO_SPECIFY_DAG
buffer[pos] |= RPL_DAO_D_FLAG;
#endif /* RPL_DAO_SPECIFY_DAG */
#if RPL_CONF_DAO_ACK
buffer[pos] |= RPL_DAO_K_FLAG;
#endif /* RPL_CONF_DAO_ACK */
++pos;
buffer[pos++] = 0; /* reserved */
buffer[pos++] = dao_sequence;
#if RPL_DAO_SPECIFY_DAG
memcpy(buffer + pos, &dag->dag_id, sizeof(dag->dag_id));
pos+=sizeof(dag->dag_id);
#endif /* RPL_DAO_SPECIFY_DAG */
/* create target subopt */
prefixlen = sizeof(*prefix) * CHAR_BIT;
buffer[pos++] = RPL_OPTION_TARGET;
buffer[pos++] = 2 + ((prefixlen + 7) / CHAR_BIT);
buffer[pos++] = 0; /* reserved */
buffer[pos++] = prefixlen;
memcpy(buffer + pos, prefix, (prefixlen + 7) / CHAR_BIT);
pos += ((prefixlen + 7) / CHAR_BIT);
/* Create a transit information sub-option. */
buffer[pos++] = RPL_OPTION_TRANSIT;
buffer[pos++] = 4;
buffer[pos++] = 0; /* flags - ignored */
buffer[pos++] = 0; /* path control - ignored */
buffer[pos++] = 0; /* path seq - ignored */
buffer[pos++] = lifetime;
PRINTF("RPL: Sending DAO with prefix ");
PRINT6ADDR(prefix);
PRINTF(" to ");
PRINT6ADDR(rpl_get_parent_ipaddr(parent));
PRINTF("\n");
if(rpl_get_parent_ipaddr(parent) != NULL) {
uip_icmp6_send(rpl_get_parent_ipaddr(parent), ICMP6_RPL, RPL_CODE_DAO, pos);
}
}
/*---------------------------------------------------------------------------*/
static void
dao_ack_input(void)
{
#if DEBUG
unsigned char *buffer;
uint8_t buffer_length;
uint8_t instance_id;
uint8_t sequence;
uint8_t status;
buffer = UIP_ICMP_PAYLOAD;
buffer_length = uip_len - uip_l3_icmp_hdr_len;
instance_id = buffer[0];
sequence = buffer[2];
status = buffer[3];
PRINTF("RPL: Received a DAO ACK with sequence number %d and status %d from ",
sequence, status);
PRINT6ADDR(&UIP_IP_BUF->srcipaddr);
PRINTF("\n");
#endif /* DEBUG */
uip_len = 0;
}
/*---------------------------------------------------------------------------*/
void
dao_ack_output(rpl_instance_t *instance, uip_ipaddr_t *dest, uint8_t sequence)
{
unsigned char *buffer;
PRINTF("RPL: Sending a DAO ACK with sequence number %d to ", sequence);
PRINT6ADDR(dest);
PRINTF("\n");
buffer = UIP_ICMP_PAYLOAD;
buffer[0] = instance->instance_id;
buffer[1] = 0;
buffer[2] = sequence;
buffer[3] = 0;
uip_icmp6_send(dest, ICMP6_RPL, RPL_CODE_DAO_ACK, 4);
}
/*---------------------------------------------------------------------------*/
void
rpl_icmp6_register_handlers()
{
uip_icmp6_register_input_handler(&dis_handler);
uip_icmp6_register_input_handler(&dio_handler);
uip_icmp6_register_input_handler(&dao_handler);
uip_icmp6_register_input_handler(&dao_ack_handler);
}
/*---------------------------------------------------------------------------*/
/** @}*/
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