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gnrc_sixlowpan_nd: initial import

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This commit is contained in:
Martine Lenders 2015-08-28 03:59:38 +02:00
parent fc6896b0c7
commit 2a1c243ad2
5 changed files with 508 additions and 1 deletions
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17
Makefile.dep
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@ -52,6 +52,7 @@ endif
ifneq (,$(filter gnrc_sixlowpan_default,$(USEMODULE)))
USEMODULE += gnrc_ipv6_default
USEMODULE += gnrc_sixlowpan
USEMODULE += gnrc_sixlowpan_nd
USEMODULE += gnrc_sixlowpan_frag
USEMODULE += gnrc_sixlowpan_iphc
endif
@ -77,10 +78,24 @@ ifneq (,$(filter gnrc_sixlowpan_ctx,$(USEMODULE)))
USEMODULE += vtimer
endif
ifneq (,$(filter gnrc_sixlowpan_nd,$(USEMODULE)))
USEMODULE += gnrc_ndp
USEMODULE += gnrc_ndp_internal
USEMODULE += gnrc_sixlowpan_ctx
USEMODULE += random
USEMODULE += vtimer
endif
ifneq (,$(filter gnrc_ipv6_default,$(USEMODULE)))
USEMODULE += gnrc_ipv6
USEMODULE += gnrc_icmpv6
USEMODULE += gnrc_ndp_host
ifeq (1,$(GNRC_NETIF_NUMOF))
ifeq (,$(filter gnrc_sixlowpan_nd,$(USEMODULE)))
USEMODULE += gnrc_ndp_host
endif
else
USEMODULE += gnrc_ndp_host
endif
endif
ifneq (,$(filter gnrc_ipv6_router_default,$(USEMODULE)))

190
sys/include/net/gnrc/sixlowpan/nd.h Normal file
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@ -0,0 +1,190 @@
/*
* Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @defgroup net_gnrc_sixlowpan_nd 6LoWPAN neighbor discovery
* @ingroup net_gnrc_sixlowpan
* @brief Neighbor Discovery Optimization for 6LoWPAN
* @see <a href="https://tools.ietf.org/html/rfc6775">
* RFC 6775
* </a>
* @{
*
* @file
* @brief General 6LoWPAN ND definitions
*
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
*/
#ifndef GNRC_SIXLOWPAN_ND_H_
#define GNRC_SIXLOWPAN_ND_H_
#include <stdint.h>
#include "kernel_types.h"
#include "net/gnrc/ipv6/nc.h"
#include "net/gnrc/ipv6/netif.h"
#include "net/ipv6/addr.h"
#include "net/ndp.h"
#include "net/sixlowpan/nd.h"
#include "timex.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Message type for next multicast router solicitation.
*/
#define GNRC_SIXLOWPAN_ND_MSG_MC_RTR_SOL (0x0220)
/**
* @brief Message type for next unicast router solicitation.
*/
#define GNRC_SIXLOWPAN_ND_MSG_UC_RTR_SOL (0x0221)
/**
* @brief Message type for removing 6LoWPAN contexts.
*/
#define GNRC_SIXLOWPAN_ND_MSG_DELETE_CTX (0x0222)
#ifndef GNRC_SIXLOWPAN_ND_AR_LTIME
/**
* @brief Registration lifetime in minutes for the address registration option
*
* This value should be adapted to the devices power-lifecycle so that it is greater than the
* time the device spends sleeping.
*
* @see <a href="https://tools.ietf.org/html/rfc6775#section-5.8.1">
* RFC 6775, section 5.8.1
* </a>
*/
#define GNRC_SIXLOWPAN_ND_AR_LTIME (15U)
#endif
/**
* @name Host constants
* @{
* @see <a href="https://tools.ietf.org/html/rfc6775#section-9">
* RFC 6775, section 9
* </a>
*/
#define GNRC_SIXLOWPAN_ND_RTR_SOL_INT (10U) /**< replacement value (in seconds) for
* @ref GNRC_NDP_MAX_RTR_SOL_INT */
#define GNRC_SIXLOWPAN_ND_MAX_RTR_SOL_INT (60U) /**< retransmission increment for exponential
* backoff of subsequent RS */
/** @} */
/**
* @brief Initializes 6LoWPAN neighbor discovery for the interface.
* @pre @p iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN
* @param[in] iface An IPv6 interface.
*/
void gnrc_sixlowpan_nd_init(gnrc_ipv6_netif_t *iface);
/**
* @brief Multicasts a router solicitation over @p iface
* @pre @p iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN
* @param[in] iface An IPv6 interface.
*/
void gnrc_sixlowpan_nd_mc_rtr_sol(gnrc_ipv6_netif_t *iface);
/**
* @brief Unicasts a router solicitation to the neighbor represented by @p nce
* @pre @p nce->iface is an IPv6 interface and @ref GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN is set
* in its flags.
* @param[in] nce The neighbor to send the router solicitation to.
*/
void gnrc_sixlowpan_nd_uc_rtr_sol(gnrc_ipv6_nc_t *nce);
/**
* @brief Get link-layer address and interface for next hop to destination
* IPv6 address.
*
* @param[out] l2addr The link-layer for the next hop to @p dst.
* @param[out] l2addr_len Length of @p l2addr.
* @param[in] iface The interface to search the next hop on.
* May be @ref KERNEL_PID_UNDEF if not specified.
* @param[in] dst An IPv6 address to search the next hop for.
*
* @return The PID of the interface, on success.
* @return -EHOSTUNREACH, if @p dst is not reachable.
* @return -ENOBUFS, if @p l2addr_len was smaller than the resulting @p l2addr
* would be long.
*/
kernel_pid_t gnrc_sixlowpan_nd_next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_len,
kernel_pid_t iface, ipv6_addr_t *dst);
/**
* @brief Reschedules the next router advertisement for a neighboring router.
*
* @pre nce != NULL && sec_delay != 0U
*
* @param[in] nce Neighbor cache entry representing the neighboring router.
* @param[in] sec_delay The delay for the next router solicitation in seconds.
*/
void gnrc_sixlowpan_nd_rtr_sol_reschedule(gnrc_ipv6_nc_t *nce, uint32_t sec_delay);
/**
* @brief Builds the address registration option.
*
* @param[in] status Status for the ARO.
* @param[in] ltime Registration lifetime for the ARO.
* @param[in] eui64 The EUI-64 for the ARO
* @param[in] next More options in the packet. NULL, if there are none.
*
* @return The pkt snip list of options, on success
* @return NULL, if packet buffer is full
*/
gnrc_pktsnip_t *gnrc_sixlowpan_nd_opt_ar_build(uint8_t status, uint16_t ltime, eui64_t *eui64,
gnrc_pktsnip_t *next);
/**
* @brief Handles address registration option.
*
* @param[in] iface The interface the ARO was received on.
* @param[in] ipv6 The IPv6 header the ARO was received in.
* @param[in] icmpv6_type Message type of the ICMPv6 message that contained.
* this message.
* @param[in] ar_opt The address registration option.
* @param[in] sl2a The link-layer source address contained in SL2A accompanying this
* option. May be NULL for icmpv6_type == ICMPV6_NBR_ADV.
* @param[in] sl2a_len Length of @p sl2a. May be 0 if sl2a == NULL.
*
* @return Status for the ARO in the replying NA (always 0 if icmpv6_type == ICMPV6_NBR_ADV).
*/
uint8_t gnrc_sixlowpan_nd_opt_ar_handle(kernel_pid_t iface, ipv6_hdr_t *ipv6,
uint8_t icmpv6_type, sixlowpan_nd_opt_ar_t *ar_opt,
uint8_t *sl2a, size_t sl2a_len);
/**
* @brief Handles 6LoWPAN context option.
*
* @param[in] icmpv6_type Message type of the ICMPv6 message that contained.
* this message.
* @param[in] ctx_opt The 6LoWPAN context option.
*
* @return true, when 6LoWPAN context option was correct.
* @return false, when it was incorrect.
*/
bool gnrc_sixlowpan_nd_opt_6ctx_handle(uint8_t icmpv6_type, sixlowpan_nd_opt_6ctx_t *ctx_opt);
/**
* @brief Handles registration calls after node-wakeup.
*
* @see <a href="https://tools.ietf.org/html/rfc6775#section-5.8.2">
* RFC 6776, section 5.8.2
* </a>
*/
void gnrc_sixlowpan_nd_wakeup(void);
#ifdef __cplusplus
}
#endif
#endif /* GNRC_SIXLOWPAN_ND_H_ */
/** @} */

3
sys/net/gnrc/Makefile
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@ -79,6 +79,9 @@ endif
ifneq (,$(filter gnrc_sixlowpan_iphc,$(USEMODULE)))
DIRS += network_layer/sixlowpan/iphc
endif
ifneq (,$(filter gnrc_sixlowpan_nd,$(USEMODULE)))
DIRS += network_layer/sixlowpan/nd
endif
ifneq (,$(filter gnrc_sixlowpan_netif,$(USEMODULE)))
DIRS += network_layer/sixlowpan/netif
endif

3
sys/net/gnrc/network_layer/sixlowpan/nd/Makefile Normal file
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@ -0,0 +1,3 @@
MODULE = gnrc_sixlowpan_nd
include $(RIOTBASE)/Makefile.base

296
sys/net/gnrc/network_layer/sixlowpan/nd/gnrc_sixlowpan_nd.c Normal file
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@ -0,0 +1,296 @@
/*
* Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @{
*
* @file
*/
#include "net/eui64.h"
#include "net/gnrc/ipv6.h"
#include "net/gnrc/ndp.h"
#include "net/gnrc/ndp/internal.h"
#include "net/gnrc/netif.h"
#include "net/gnrc/sixlowpan.h"
#include "net/gnrc/sixlowpan/ctx.h"
#include "random.h"
#include "timex.h"
#include "net/gnrc/sixlowpan/nd.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
static inline void _rtr_sol_reschedule(gnrc_ipv6_netif_t *iface, uint32_t sec_delay)
{
vtimer_remove(&iface->rtr_sol_timer);
vtimer_set_msg(&iface->rtr_sol_timer, timex_set(sec_delay, 0), gnrc_ipv6_pid,
GNRC_SIXLOWPAN_ND_MSG_MC_RTR_SOL, iface);
}
static inline uint32_t _binary_exp_backoff(uint32_t base_sec, unsigned int exp)
{
return genrand_uint32_range(0, (1 << exp) - 1) * base_sec;
}
static inline void _revert_iid(uint8_t *iid)
{
iid[0] ^= 0x02;
}
void gnrc_sixlowpan_nd_init(gnrc_ipv6_netif_t *iface)
{
assert(iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN);
mutex_lock(&iface->mutex);
iface->rtr_sol_count = 0; /* first will be send immediately */
DEBUG("6lo nd: retransmit multicast rtr sol in 10 sec\n");
_rtr_sol_reschedule(iface, GNRC_SIXLOWPAN_ND_RTR_SOL_INT);
mutex_unlock(&iface->mutex);
gnrc_ndp_internal_send_rtr_sol(iface->pid, NULL);
}
void gnrc_sixlowpan_nd_mc_rtr_sol(gnrc_ipv6_netif_t *iface)
{
uint32_t interval;
assert(iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN);
mutex_lock(&iface->mutex);
if (iface->rtr_sol_count < GNRC_NDP_MAX_RTR_SOL_NUMOF) {
DEBUG("6lo nd: retransmit multicast rtr sol in 10 sec\n");
iface->rtr_sol_count++;
interval = GNRC_SIXLOWPAN_ND_RTR_SOL_INT;
}
else {
unsigned int exp = (unsigned int)(iface->rtr_sol_count - GNRC_NDP_MAX_RTR_SOL_NUMOF);
interval = _binary_exp_backoff(1, exp);
if (((1U << exp) - 1U) < GNRC_SIXLOWPAN_ND_MAX_RTR_SOL_INT) {
/* XXX Not sure if this is the correct interpretation of the truncation described in
* https://tools.ietf.org/html/rfc6775#section-5.3. In every source I've read the
* truncating value was the exponent, not the target value, so I'm very confused
* about this sentencing. Anyway, since 60 sec is a maximum value this should only
* affect the energy consumption of the implementation by sending the next RS too fast
* but not its interoperability. */
iface->rtr_sol_count++;
}
DEBUG("6lo nd: retransmit multicast rtr sol in %" PRIu32 " sec\n", interval);
iface->rtr_sol_count--;
}
_rtr_sol_reschedule(iface, interval);
mutex_unlock(&iface->mutex);
gnrc_ndp_internal_send_rtr_sol(iface->pid, NULL);
}
void gnrc_sixlowpan_nd_uc_rtr_sol(gnrc_ipv6_nc_t *nce)
{
assert(gnrc_ipv6_netif_get(nce->iface)->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN);
/* neighbor is not a router anymore */
if (!(nce->flags & GNRC_IPV6_NC_IS_ROUTER) || ipv6_addr_is_unspecified(&nce->ipv6_addr)) {
/* and there are no routers anymore */
if (gnrc_ipv6_nc_get_next_router(NULL) == NULL) {
/* start search for routers */
gnrc_sixlowpan_nd_init(gnrc_ipv6_netif_get(nce->iface));
}
/* otherwise ignore this call */
return;
}
/* next RS is rescheduled by RA handle function */
gnrc_ndp_internal_send_rtr_sol(nce->iface, &nce->ipv6_addr);
}
kernel_pid_t gnrc_sixlowpan_nd_next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_len,
kernel_pid_t iface, ipv6_addr_t *dst)
{
ipv6_addr_t *next_hop = NULL;
gnrc_ipv6_nc_t *nc_entry = NULL;
#ifdef MODULE_GNRC_IPV6_EXT_RH
ipv6_hdr_t *hdr;
gnrc_pktsnip_t *ipv6;
LL_SEARCH_SCALAR(pkt, ipv6, type, GNRC_NETTYPE_IPV6);
assert(ipv6);
hdr = ipv6->data;
next_hop = ipv6_ext_rh_next_hop(hdr);
#endif
#ifdef MODULE_FIB
ipv6_addr_t next_hop_actual; /* FIB copies address into this variable */
/* don't look-up link local addresses in FIB */
if ((next_hop == NULL) && !ipv6_addr_is_link_local(dst)) {
size_t next_hop_size = sizeof(ipv6_addr_t);
uint32_t next_hop_flags = 0;
if ((next_hop == NULL) &&
(fib_get_next_hop(&gnrc_ipv6_fib_table, &iface, next_hop_actual.u8, &next_hop_size,
&next_hop_flags, (uint8_t *)dst,
sizeof(ipv6_addr_t), 0) >= 0) &&
(next_hop_size == sizeof(ipv6_addr_t))) {
next_hop = &next_hop_actual;
}
}
#endif
/* next hop determination according to: https://tools.ietf.org/html/rfc6775#section-5.6 */
if ((next_hop == NULL) && ipv6_addr_is_link_local(dst)) { /* prefix is "on-link" */
/* multicast is not handled here anyway so we don't need to check that */
next_hop = dst;
}
else if (next_hop == NULL) { /* prefix is off-link */
next_hop = gnrc_ndp_internal_default_router();
}
/* address resolution of next_hop: https://tools.ietf.org/html/rfc6775#section-5.7 */
if (ipv6_addr_is_link_local(next_hop)) {
kernel_pid_t ifs[GNRC_NETIF_NUMOF];
size_t ifnum = gnrc_netif_get(ifs);
/* we don't need address resolution, the EUI-64 is in next_hop's IID */
*l2addr_len = sizeof(eui64_t);
memcpy(l2addr, &next_hop->u8[8], sizeof(eui64_t));
_revert_iid(l2addr);
if (iface == KERNEL_PID_UNDEF) {
for (unsigned i = 0; i < ifnum; i++) {
gnrc_ipv6_netif_t *ipv6_if = gnrc_ipv6_netif_get(ifs[i]);
if ((ipv6_if != NULL) && (ipv6_if->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN)) {
/* always take the first 6LoWPAN interface we can find */
return ifs[i];
}
}
}
return iface;
}
else {
nc_entry = gnrc_ipv6_nc_get(iface, next_hop);
if ((nc_entry == NULL) || (!gnrc_ipv6_nc_is_reachable(nc_entry))) {
return KERNEL_PID_UNDEF;
}
if (nc_entry->l2_addr_len > 0) {
memcpy(l2addr, nc_entry->l2_addr, nc_entry->l2_addr_len);
}
*l2addr_len = nc_entry->l2_addr_len;
return nc_entry->iface;
}
}
void gnrc_sixlowpan_nd_rtr_sol_reschedule(gnrc_ipv6_nc_t *nce, uint32_t sec_delay)
{
assert(nce != NULL);
assert(sec_delay != 0U);
vtimer_remove(&nce->rtr_sol_timer);
vtimer_set_msg(&nce->rtr_sol_timer, timex_set(sec_delay, 0), gnrc_ipv6_pid,
GNRC_SIXLOWPAN_ND_MSG_MC_RTR_SOL, nce);
}
gnrc_pktsnip_t *gnrc_sixlowpan_nd_opt_ar_build(uint8_t status, uint16_t ltime, eui64_t *eui64,
gnrc_pktsnip_t *next)
{
gnrc_pktsnip_t *pkt = gnrc_ndp_opt_build(NDP_OPT_AR, sizeof(sixlowpan_nd_opt_ar_t), next);
if (pkt != NULL) {
sixlowpan_nd_opt_ar_t *ar_opt = pkt->data;
ar_opt->status = status;
ar_opt->resv[0] = ar_opt->resv[1] = ar_opt->resv[2] = 0;
ar_opt->ltime = byteorder_htons(ltime);
memcpy(&ar_opt->eui64, eui64, sizeof(eui64_t));
}
return pkt;
}
uint8_t gnrc_sixlowpan_nd_opt_ar_handle(kernel_pid_t iface, ipv6_hdr_t *ipv6, uint8_t icmpv6_type,
sixlowpan_nd_opt_ar_t *ar_opt, uint8_t *sl2a,
size_t sl2a_len)
{
eui64_t eui64;
gnrc_ipv6_netif_t *ipv6_iface;
gnrc_ipv6_nc_t *nc_entry;
(void)sl2a;
(void)sl2a_len;
if (ar_opt->len != SIXLOWPAN_ND_OPT_AR_LEN) {
/* discard silently: see https://tools.ietf.org/html/rfc6775#section-5.5.2 */
return 0;
}
if (gnrc_netapi_get(iface, NETOPT_ADDRESS_LONG, 0, &eui64,
sizeof(eui64)) < 0) {
/* discard silently: see https://tools.ietf.org/html/rfc6775#section-5.5.2 */
return 0;
}
ipv6_iface = gnrc_ipv6_netif_get(iface);
nc_entry = gnrc_ipv6_nc_get(iface, &ipv6->src);
switch (icmpv6_type) {
case ICMPV6_NBR_ADV:
if (!(ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN)) {
DEBUG("6lo nd: interface not a 6LoWPAN interface\n");
return 0;
}
if (eui64.uint64.u64 != ar_opt->eui64.uint64.u64) {
/* discard silently: see https://tools.ietf.org/html/rfc6775#section-5.5.2 */
return 0;
}
switch (ar_opt->status) {
case SIXLOWPAN_ND_STATUS_SUCCESS:
DEBUG("6lo nd: address registration successful\n");
mutex_lock(&ipv6_iface->mutex);
vtimer_remove(&nc_entry->nbr_sol_timer);
vtimer_set_msg(&nc_entry->nbr_sol_timer, ipv6_iface->retrans_timer,
gnrc_ipv6_pid, GNRC_NDP_MSG_NBR_SOL_RETRANS, nc_entry);
mutex_unlock(&ipv6_iface->mutex);
break;
case SIXLOWPAN_ND_STATUS_DUP:
DEBUG("6lo nd: address registration determined duplicated\n");
/* TODO: handle DAD failed case */
gnrc_ipv6_netif_remove_addr(iface, &ipv6->dst);
/* address should not be used anymore */
break;
case SIXLOWPAN_ND_STATUS_NC_FULL:
DEBUG("6lo nd: neighbor cache on router is full\n");
gnrc_ipv6_nc_remove(iface, &ipv6->src);
/* try to find another router */
gnrc_sixlowpan_nd_init(ipv6_iface);
break;
default:
DEBUG("6lo nd: unknown status for registration received\n");
break;
}
default:
break;
}
return 0;
}
bool gnrc_sixlowpan_nd_opt_6ctx_handle(uint8_t icmpv6_type, sixlowpan_nd_opt_6ctx_t *ctx_opt)
{
if (((ctx_opt->ctx_len < 64) && (ctx_opt->len != 2)) ||
((ctx_opt->ctx_len >= 64) && (ctx_opt->len != 3))) {
DEBUG("6lo nd: invalid 6LoWPAN context option received\n");
return false;
}
if (icmpv6_type != ICMPV6_RTR_ADV) {
/* discard silently */
return true;
}
/* don't care for result */
gnrc_sixlowpan_ctx_update(sixlowpan_nd_opt_6ctx_get_cid(ctx_opt), (ipv6_addr_t *)(ctx_opt + 1),
ctx_opt->ctx_len, byteorder_ntohs(ctx_opt->ltime),
sixlowpan_nd_opt_6ctx_is_comp(ctx_opt));
return true;
}
void gnrc_sixlowpan_nd_wakeup(void)
{
gnrc_ipv6_nc_t *router = gnrc_ipv6_nc_get_next_router(NULL);
while (router) {
timex_t t = { 0, GNRC_NDP_RETRANS_TIMER };
vtimer_remove(&router->rtr_sol_timer);
gnrc_sixlowpan_nd_uc_rtr_sol(router);
gnrc_ndp_internal_send_nbr_sol(router->iface, &router->ipv6_addr, &router->ipv6_addr);
vtimer_remove(&router->nbr_sol_timer);
vtimer_set_msg(&router->nbr_sol_timer, t, gnrc_ipv6_pid, GNRC_NDP_MSG_NBR_SOL_RETRANS,
router);
}
}
/** @} */