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ng_ndp: add support for address-less link-layers

dev/timer
Martine Lenders 8 years ago
parent
commit
a980155250
  1. 22
      sys/include/net/gnrc/ndp/internal.h
  2. 163
      sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
  3. 40
      sys/net/gnrc/network_layer/ndp/internal/gnrc_ndp_internal.c
  4. 6
      sys/net/gnrc/network_layer/ndp/node/gnrc_ndp_node.c

22
sys/include/net/gnrc/ndp/internal.h

@ -19,8 +19,8 @@
*
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
*/
#ifndef INTERNAL_H_
#define INTERNAL_H_
#ifndef GNRC_NDP_INTERNAL_H_
#define GNRC_NDP_INTERNAL_H_
#include "net/ipv6/addr.h"
#include "net/ipv6/hdr.h"
@ -91,23 +91,22 @@ void gnrc_ndp_internal_send_nbr_adv(kernel_pid_t iface, ipv6_addr_t *tgt, ipv6_a
/**
* @brief Handles a SL2A option.
*
* @param[in] iface Interface the option was received on.
* @param[in] pkt Packet the option was received in.
* @param[in] ipv6 IPv6 header of @p pkt
* @param[in] icmpv6_type ICMPv6 type of the message carrying the option.
* @param[in] sl2a_opt The SL2A option.
* @param[in] tl2a_opt The TL2A option.
* @param[out] l2addr The L2 address carried in the SL2A option.
*
* @return true, on success.
* @return false, if SL2A was not valid.
* @return length of the L2 address, on success.
* @return -EINVAL, if SL2A was not valid.
* @return -ENOTSUP, if node should silently ignore the option.
*/
bool gnrc_ndp_internal_sl2a_opt_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, uint8_t icmpv6_type,
ndp_opt_t *sl2a_opt);
int gnrc_ndp_internal_sl2a_opt_handle(gnrc_pktsnip_t *pkt, ipv6_hdr_t *ipv6, uint8_t icmpv6_type,
ndp_opt_t *sl2a_opt, uint8_t *l2addr);
/**
* @brief Handles a TL2A option.
*
* @param[in] iface Interface the option was received on.
* @param[in] pkt Packet the option was received in.
* @param[in] ipv6 IPv6 header of @p pkt
* @param[in] icmpv6_type ICMPv6 type of the message carrying the option.
@ -116,6 +115,7 @@ bool gnrc_ndp_internal_sl2a_opt_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
*
* @return length of the L2 address, on success.
* @return -EINVAL, if TL2A was not valid.
* @return -ENOTSUP, if node should silently ignore the option.
*/
int gnrc_ndp_internal_tl2a_opt_handle(gnrc_pktsnip_t *pkt, ipv6_hdr_t *ipv6,
uint8_t icmpv6_type, ndp_opt_t *tl2a_opt,
@ -125,5 +125,5 @@ int gnrc_ndp_internal_tl2a_opt_handle(gnrc_pktsnip_t *pkt, ipv6_hdr_t *ipv6,
}
#endif
#endif /* INTERNAL_H_ */
#endif /* GNRC_NDP_INTERNAL_H_ */
/** @} */

163
sys/net/gnrc/network_layer/ndp/gnrc_ndp.c

@ -43,23 +43,42 @@
static char addr_str[IPV6_ADDR_MAX_STR_LEN];
#endif
/* random helper function */
/* sets an entry to stale if its l2addr differs from the given one or creates it stale if it
* does not exist */
static void _stale_nc(kernel_pid_t iface, ipv6_addr_t *ipaddr, uint8_t *l2addr,
int l2addr_len)
{
if (l2addr_len != -ENOTSUP) {
gnrc_ipv6_nc_t *nc_entry = gnrc_ipv6_nc_get(iface, ipaddr);
if (nc_entry == NULL) {
gnrc_ipv6_nc_add(iface, ipaddr, l2addr, (uint16_t)l2addr_len,
GNRC_IPV6_NC_STATE_STALE);
}
else if (((uint16_t)l2addr_len != nc_entry->l2_addr_len) ||
(memcmp(l2addr, nc_entry->l2_addr, l2addr_len) != 0)) {
/* if entry exists but l2 address differs: set */
nc_entry->l2_addr_len = (uint16_t)l2addr_len;
memcpy(nc_entry->l2_addr, l2addr, l2addr_len);
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
}
}
void gnrc_ndp_nbr_sol_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, ndp_nbr_sol_t *nbr_sol,
size_t icmpv6_size)
{
uint16_t opt_offset = 0;
uint8_t l2src[GNRC_IPV6_NC_L2_ADDR_MAX];
uint8_t *buf = ((uint8_t *)nbr_sol) + sizeof(ndp_nbr_sol_t);
ipv6_addr_t *tgt;
int sicmpv6_size = (int)icmpv6_size;
int sicmpv6_size = (int)icmpv6_size, l2src_len = 0;
DEBUG("ndp: received neighbor solicitation (src: %s, ",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG("dst: %s, ",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
DEBUG("tgt: %s)\n",
ipv6_addr_to_str(addr_str, &nbr_sol->tgt, sizeof(addr_str)));
/* check validity */
if ((ipv6->hl != 255) || (nbr_sol->code != 0) ||
(icmpv6_size < sizeof(ndp_nbr_sol_t)) ||
@ -70,41 +89,37 @@ void gnrc_ndp_nbr_sol_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
/* ipv6 releases */
return;
}
if ((tgt = gnrc_ipv6_netif_find_addr(iface, &nbr_sol->tgt)) == NULL) {
DEBUG("ndp: Target address is not to interface %" PRIkernel_pid "\n",
iface);
/* ipv6 releases */
return;
}
sicmpv6_size -= sizeof(ndp_nbr_sol_t);
while (sicmpv6_size > 0) {
ndp_opt_t *opt = (ndp_opt_t *)(buf + opt_offset);
switch (opt->type) {
case NDP_OPT_SL2A:
if (!gnrc_ndp_internal_sl2a_opt_handle(iface, pkt, ipv6, nbr_sol->type, opt)) {
/* invalid source link-layer address option */
if ((l2src_len = gnrc_ndp_internal_sl2a_opt_handle(pkt, ipv6, nbr_sol->type, opt,
l2src)) < 0) {
/* -ENOTSUP can not happen, since the function only returns this for invalid
* message types containing the SL2A. Neighbor solicitations are not an
* invalid message type for SL2A. According to that, we don't need to watch
* out for that here, but regardless, the source link-layer address option
* is invalid. */
return;
}
break;
default:
/* silently discard all other options */
break;
}
opt_offset += (opt->len * 8);
sicmpv6_size -= (opt->len * 8);
}
_stale_nc(iface, &ipv6->src, l2src, l2src_len);
gnrc_ndp_internal_send_nbr_adv(iface, tgt, &ipv6->src, ipv6_addr_is_multicast(&ipv6->dst),
NULL);
return;
}
static inline bool _pkt_has_l2addr(gnrc_netif_hdr_t *netif_hdr)
@ -178,66 +193,24 @@ void gnrc_ndp_nbr_adv_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
netif_hdr = netif->data;
}
if (gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_INCOMPLETE) {
gnrc_pktqueue_t *queued_pkt;
if (_pkt_has_l2addr(netif_hdr) && (l2tgt_len == 0)) {
/* link-layer has addresses, but no TLLAO supplied: discard silently
* (see https://tools.ietf.org/html/rfc4861#section-7.2.5) */
return;
}
nc_entry->iface = iface;
nc_entry->l2_addr_len = l2tgt_len;
memcpy(nc_entry->l2_addr, l2tgt, l2tgt_len);
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_S) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_REACHABLE);
}
else {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
if (l2tgt_len != -ENOTSUP) {
if (gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_INCOMPLETE) {
gnrc_pktqueue_t *queued_pkt;
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_R) {
nc_entry->flags |= GNRC_IPV6_NC_IS_ROUTER;
}
else {
nc_entry->flags &= ~GNRC_IPV6_NC_IS_ROUTER;
/* TODO: update FIB */
}
while ((queued_pkt = gnrc_pktqueue_remove_head(&nc_entry->pkts)) != NULL) {
gnrc_netapi_send(gnrc_ipv6_pid, queued_pkt->pkt);
queued_pkt->pkt = NULL;
}
}
else {
/* first or-term: no link-layer, but nc_entry has l2addr,
* second or-term: different l2addr cached */
bool l2tgt_changed = false;
if ((!_pkt_has_l2addr(netif_hdr)) && (l2tgt_len == 0)) {
/* there was previously a L2 address registered */
l2tgt_changed = (nc_entry->l2_addr_len != 0);
}
/* link-layer has addresses and TLLAO with different address */
else if (_pkt_has_l2addr(netif_hdr) && (l2tgt_len != 0)) {
l2tgt_changed = (!(l2tgt_len == nc_entry->l2_addr_len)) &&
(memcmp(nc_entry->l2_addr, l2tgt, l2tgt_len) == 0);
}
if ((nbr_adv->flags & NDP_NBR_ADV_FLAGS_O) || !l2tgt_changed ||
(l2tgt_len == 0)) {
if (l2tgt_len != 0) {
nc_entry->iface = iface;
nc_entry->l2_addr_len = l2tgt_len;
memcpy(nc_entry->l2_addr, l2tgt, l2tgt_len);
if (_pkt_has_l2addr(netif_hdr) && (l2tgt_len == 0)) {
/* link-layer has addresses, but no TLLAO supplied: discard silently
* (see https://tools.ietf.org/html/rfc4861#section-7.2.5) */
return;
}
nc_entry->iface = iface;
nc_entry->l2_addr_len = l2tgt_len;
memcpy(nc_entry->l2_addr, l2tgt, l2tgt_len);
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_S) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_REACHABLE);
}
else if (l2tgt_changed && (l2tgt_len != 0)) {
else {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
@ -246,13 +219,55 @@ void gnrc_ndp_nbr_adv_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
}
else {
nc_entry->flags &= ~GNRC_IPV6_NC_IS_ROUTER;
/* TODO: update FIB */
/* TODO: update state of neighbor as router in FIB? */
}
while ((queued_pkt = gnrc_pktqueue_remove_head(&nc_entry->pkts)) != NULL) {
gnrc_netapi_send(gnrc_ipv6_pid, queued_pkt->pkt);
queued_pkt->pkt = NULL;
}
}
else if (l2tgt_changed) {
if (gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_REACHABLE) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
else {
/* first or-term: no link-layer, but nc_entry has l2addr,
* second or-term: different l2addr cached */
bool l2tgt_changed = false;
if ((!_pkt_has_l2addr(netif_hdr)) && (l2tgt_len == 0)) {
/* there was previously a L2 address registered */
l2tgt_changed = (nc_entry->l2_addr_len != 0);
}
/* link-layer has addresses and TLLAO with different address */
else if (_pkt_has_l2addr(netif_hdr) && (l2tgt_len != 0)) {
l2tgt_changed = (!(l2tgt_len == nc_entry->l2_addr_len)) &&
(memcmp(nc_entry->l2_addr, l2tgt, l2tgt_len) == 0);
}
if ((nbr_adv->flags & NDP_NBR_ADV_FLAGS_O) || !l2tgt_changed ||
(l2tgt_len == 0)) {
if (l2tgt_len != 0) {
nc_entry->iface = iface;
nc_entry->l2_addr_len = l2tgt_len;
memcpy(nc_entry->l2_addr, l2tgt, l2tgt_len);
}
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_S) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_REACHABLE);
}
else if (l2tgt_changed) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_R) {
nc_entry->flags |= GNRC_IPV6_NC_IS_ROUTER;
}
else {
nc_entry->flags &= ~GNRC_IPV6_NC_IS_ROUTER;
/* TODO: update state of neighbor as router in FIB? */
}
}
else if (l2tgt_changed &&
gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_REACHABLE) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
}
}

40
sys/net/gnrc/network_layer/ndp/internal/gnrc_ndp_internal.c

@ -311,17 +311,15 @@ void gnrc_ndp_internal_send_nbr_sol(kernel_pid_t iface, ipv6_addr_t *tgt,
gnrc_netapi_send(gnrc_ipv6_pid, pkt);
}
bool gnrc_ndp_internal_sl2a_opt_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, uint8_t icmpv6_type,
ndp_opt_t *sl2a_opt)
int gnrc_ndp_internal_sl2a_opt_handle(gnrc_pktsnip_t *pkt, ipv6_hdr_t *ipv6, uint8_t icmpv6_type,
ndp_opt_t *sl2a_opt, uint8_t *l2src)
{
gnrc_ipv6_nc_t *nc_entry = NULL;
uint8_t sl2a_len = 0;
int sl2a_len = 0;
uint8_t *sl2a = (uint8_t *)(sl2a_opt + 1);
if ((sl2a_opt->len == 0) || ipv6_addr_is_unspecified(&ipv6->src)) {
DEBUG("ndp: invalid source link-layer address option received\n");
return false;
return -EINVAL;
}
while (pkt) {
@ -333,41 +331,25 @@ bool gnrc_ndp_internal_sl2a_opt_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
pkt = pkt->next;
}
if (sl2a_len == 0) { /* in case there was no source address in l2 */
sl2a_len = (sl2a_opt->len / 8) - sizeof(ndp_opt_t);
/* ignore all zeroes at the end for length */
for (; sl2a[sl2a_len - 1] == 0x00; sl2a_len--);
}
DEBUG("ndp: received SL2A (link-layer address: %s)\n",
gnrc_netif_addr_to_str(addr_str, sizeof(addr_str), sl2a, sl2a_len));
switch (icmpv6_type) {
case ICMPV6_NBR_SOL:
nc_entry = gnrc_ipv6_nc_get(iface, &ipv6->src);
if (sl2a_len == 0) { /* in case there was no source address in l2 */
sl2a_len = (sl2a_opt->len / 8) - sizeof(ndp_opt_t);
if (nc_entry != NULL) {
if ((sl2a_len != nc_entry->l2_addr_len) ||
(memcmp(sl2a, nc_entry->l2_addr, sl2a_len) != 0)) {
/* if entry exists but l2 address differs: set */
nc_entry->l2_addr_len = sl2a_len;
memcpy(nc_entry->l2_addr, sl2a, sl2a_len);
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
}
else {
gnrc_ipv6_nc_add(iface, &ipv6->src, sl2a, sl2a_len,
GNRC_IPV6_NC_STATE_STALE);
/* ignore all zeroes at the end for length */
for (; sl2a[sl2a_len - 1] == 0x00; sl2a_len--);
}
return true;
memcpy(l2src, sl2a, sl2a_len);
return sl2a_len;
default: /* wrong encapsulating message: silently discard */
DEBUG("ndp: silently discard sl2a_opt for ICMPv6 message type %"
PRIu8 "\n", icmpv6_type);
return true;
return -ENOTSUP;
}
}

6
sys/net/gnrc/network_layer/ndp/node/gnrc_ndp_node.c

@ -109,7 +109,6 @@ kernel_pid_t gnrc_ndp_node_next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_len,
next_hop_ip = gnrc_ndp_internal_default_router();
}
if (next_hop_ip == NULL) {
next_hop_ip = dst; /* Just look if it's in the neighbor cache
* (aka on-link but not registered in prefix list as such) */
@ -128,8 +127,9 @@ kernel_pid_t gnrc_ndp_node_next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_len,
if (gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_STALE) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_DELAY);
}
memcpy(l2addr, nc_entry->l2_addr, nc_entry->l2_addr_len);
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;
/* TODO: unreachability check */
return nc_entry->iface;

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