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/*
* 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_ndp IPv6 Neighbor discovery
* @ingroup net_gnrc_icmpv6
* @brief GNRC's IPv6 Neighbor Discovery implementation
* @{
*
* @file
* @brief Definitions for GNRC's IPv6 Neighbor Discovery
*
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
*/
#ifndef GNRC_NDP_H_
#define GNRC_NDP_H_
#include <inttypes.h>
#include <stdlib.h>
#include "byteorder.h"
#include "net/ndp.h"
#include "net/gnrc/pkt.h"
#include "net/gnrc/icmpv6.h"
#include "net/ipv6/addr.h"
#include "net/gnrc/ipv6/nc.h"
#include "net/gnrc/ipv6/netif.h"
#include "net/gnrc/ndp/host.h"
#include "net/gnrc/ndp/internal.h"
#include "net/gnrc/ndp/router.h"
#include "net/gnrc/ndp/node.h"
#ifdef __cplusplus
extern "C" {
#endif
/** Message type for router timeouts */
#define GNRC_NDP_MSG_RTR_TIMEOUT (0x0210)
/** Message type for address timeouts */
#define GNRC_NDP_MSG_ADDR_TIMEOUT (0x0211)
/** Message type for multicast neighbor solicitation retransmissions */
#define GNRC_NDP_MSG_NBR_SOL_RETRANS (0x0212)
/** Message type for periodic router advertisements */
#define GNRC_NDP_MSG_RTR_ADV_RETRANS (0x0213)
/** Message type for delayed router advertisements */
#define GNRC_NDP_MSG_RTR_ADV_DELAY (0x0214)
/** Message type for delayed router advertisements in a 6LoWPAN
* 6LoWPAN needs a special handling, because router advertisements are only
* sent after a short randomized delay, but not periodically. */
#define GNRC_NDP_MSG_RTR_ADV_SIXLOWPAN_DELAY (0x0215)
/** Message type for periodic router solicitations */
#define GNRC_NDP_MSG_RTR_SOL_RETRANS (0x0216)
/** Message type for neighbor cache state timeouts */
#define GNRC_NDP_MSG_NC_STATE_TIMEOUT (0x0217)
/**
* @name Host constants
* @{
* @see <a href="https://tools.ietf.org/html/rfc4861#section-10">
* RFC 4861, section 10
* </a>
*/
/**
* @brief Upper bound for randomised delay in seconds for initial
* router solicitation transmissions
*/
#define GNRC_NDP_MAX_RTR_SOL_DELAY (1U)
/**
* @brief Interval in seconds between initial router solicitation
* transmissions
*/
#define GNRC_NDP_MAX_RTR_SOL_INT (4U)
/**
* @brief Maximum number of initial router solicitation transmissions
*/
#define GNRC_NDP_MAX_RTR_SOL_NUMOF (3U)
/** @} */
/**
* @name Node constants
* @{
* @see <a href="https://tools.ietf.org/html/rfc4861#section-10">
* RFC 4861, section 10
* </a>
*/
/**
* @brief Maximum number of unanswered multicast neighbor solicitations
* before address resolution is considered failed.
*/
#define GNRC_NDP_MAX_MC_NBR_SOL_NUMOF (3U)
/**
* @brief Maximum number of unanswered unicast neighbor solicitations before
* an address is considered unreachable.
*/
#define GNRC_NDP_MAX_UC_NBR_SOL_NUMOF (3U)
/**
* @brief Upper bound of randomized delay in seconds for a solicited
* neighbor advertisement transmission for an anycast target.
*/
#define GNRC_NDP_MAX_AC_TGT_DELAY (1U)
/**
* @brief Maximum number of unsolicited neighbor advertisements before on
* link-layer address change.
*/
#define GNRC_NDP_MAX_NBR_ADV_NUMOF (3U)
/**
* @brief Base value in mircoseconds for computing randomised
* reachable time.
*/
#define GNRC_NDP_REACH_TIME (30U * US_PER_SEC)
/**
* @brief Time in mircoseconds between retransmissions of neighbor
* solicitations to a neighbor.
*/
#define GNRC_NDP_RETRANS_TIMER (1U * US_PER_SEC)
/**
* @brief Delay in seconds for neighbor cache entry between entering
* DELAY state and entering PROBE state if no reachability
* confirmation has been received.
*/
#define GNRC_NDP_FIRST_PROBE_DELAY (5U)
/**
* @brief Lower bound for randomised reachable time calculation.
*/
#define GNRC_NDP_MIN_RAND (5U)
/**
* @brief Upper bound for randomised reachable time calculation.
*/
#define GNRC_NDP_MAX_RAND (15U)
/** @} */
/**
* @name Router constants
* @{
* @see <a href="https://tools.ietf.org/html/rfc4861#section-10">
* RFC 4861, section 10
* </a>
*/
/**
* @brief Initial router advertisement interval in seconds
*/
#define GNRC_NDP_MAX_INIT_RTR_ADV_INT (16U)
/**
* @brief Maximum number of initial router advertisement transmissions
*/
#define GNRC_NDP_MAX_INIT_RTR_ADV_NUMOF (3U)
/**
* @brief Maximum number of final router advertisement transmissions
*/
#define GNRC_NDP_MAX_FIN_RTR_ADV_NUMOF (3U)
/**
* @brief Minimum delay in seconds between router advertisement
* transmissions
*/
#define GNRC_NDP_MIN_RTR_ADV_DELAY (3U)
/**
* @brief Upper bound for randomised delay in microseconds between router
* solicitation reception and responding router advertisement
* transmission.
*/
#define GNRC_NDP_MAX_RTR_ADV_DELAY (500U * US_PER_MS)
/** @} */
/**
* @brief Handles received neighbor solicitations.
*
* @param[in] iface The receiving interface.
* @param[in] pkt The received packet.
* @param[in] ipv6 The IPv6 header in @p pkt.
* @param[in] nbr_sol The neighbor solicitation in @p pkt.
* @param[in] icmpv6_size The overall size of the neighbor solicitation.
*/
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);
/**
* @brief Handles received neighbor advertisements.
*
* @param[in] iface The receiving interface.
* @param[in] pkt The received packet.
* @param[in] ipv6 The IPv6 header in @p pkt.
* @param[in] nbr_adv The neighbor advertisement in @p pkt.
* @param[in] icmpv6_size The overall size of the neighbor advertisement.
*/
void gnrc_ndp_nbr_adv_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, ndp_nbr_adv_t *nbr_adv,
size_t icmpv6_size);
#if (defined(MODULE_GNRC_NDP_ROUTER) || defined(MODULE_GNRC_SIXLOWPAN_ND_ROUTER))
/**
* @brief Handles received router solicitations.
*
* @param[in] iface The receiving interface.
* @param[in] pkt The received packet.
* @param[in] ipv6 The IPv6 header in @p pkt.
* @param[in] rtr_sol The router solicitation in @p pkt.
* @param[in] icmpv6_size The overall size of the router solicitation.
*/
void gnrc_ndp_rtr_sol_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, ndp_rtr_sol_t *rtr_sol,
size_t icmpv6_size);
#else
/**
* @brief A host *must* silently discard all received router solicitations.
* @see <a href="https://tools.ietf.org/html/rfc4861#section-6.2.6">
* RFC 4861, section 6.2.6
* </a>
*
* This macro is primarily an optimization to not go into the function defined
* above.
*/
#define gnrc_ndp_rtr_sol_handle(iface, pkt, ipv6, rtr_sol, size)
#endif
/**
* @brief Handles received router advertisements
*
* @todo As router check consistency as described in RFC 4861, section 6.2.3
*
* @param[in] iface The receiving interface.
* @param[in] pkt The received packet.
* @param[in] ipv6 The IPv6 header in @p pkt.
* @param[in] rtr_adv The router advertisement in @p pkt.
* @param[in] icmpv6_size The overall size of the router advertisement.
*/
void gnrc_ndp_rtr_adv_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, ndp_rtr_adv_t *rtr_adv,
size_t icmpv6_size);
/**
* @brief Retransmits a multicast neighbor solicitation for an incomplete or
* probing neighbor cache entry @p nc_entry,
* if nc_entry::probes_remaining > 0.
*
* @details If nc_entry::probes_remaining > 0 it will be decremented. If it
* reaches 0 it the entry @p nc_entry will be removed from the
* neighbor cache.
*
* @param[in] nc_entry A neighbor cache entry. Will be ignored if its state
* is not @ref GNRC_IPV6_NC_STATE_INCOMPLETE or
* @ref GNRC_IPV6_NC_STATE_PROBE.
*/
void gnrc_ndp_retrans_nbr_sol(gnrc_ipv6_nc_t *nc_entry);
/**
* @brief Event handler for a neighbor cache state timeout.
*
* @param[in] nc_entry A neighbor cache entry.
*/
void gnrc_ndp_state_timeout(gnrc_ipv6_nc_t *nc_entry);
/**
* @brief NDP interface initialization.
*
* @param[in] iface An IPv6 interface descriptor. Must not be NULL.
*/
void gnrc_ndp_netif_add(gnrc_ipv6_netif_t *iface);
/**
* @brief NDP interface removal.
*
* @param[in] iface An IPv6 interface descriptor. Must not be NULL.
*/
void gnrc_ndp_netif_remove(gnrc_ipv6_netif_t *iface);
/**
* @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.
* @param[in] pkt Packet to send to @p dst. Leave NULL if you
* just want to get the addresses.
*
* @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_ndp_next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_len,
kernel_pid_t iface, ipv6_addr_t *dst,
gnrc_pktsnip_t *pkt);
/**
* @brief Builds a neighbor solicitation message for sending.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.3">
* RFC 4861, section 4.3
* </a>
*
* @param[in] tgt The target address.
* @param[in] options Options to append to the router solicitation.
*
* @return The resulting ICMPv6 packet on success.
* @return NULL, on failure.
*/
gnrc_pktsnip_t *gnrc_ndp_nbr_sol_build(ipv6_addr_t *tgt, gnrc_pktsnip_t *options);
/**
* @brief Builds a neighbor advertisement message for sending.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.4">
* RFC 4861, section 4.4
* </a>
*
* @param[in] flags Neighbor advertisement flags:
* @ref NDP_NBR_ADV_FLAGS_R == 1 indicates, that the
* sender is a router,
* @ref NDP_NBR_ADV_FLAGS_S == 1 indicates that the
* advertisement was sent in response to a neighbor
* solicitation,
* @ref NDP_NBR_ADV_FLAGS_O == 1 indicates that the
* advertisement should override an existing cache entry
* and update the cached link-layer address.
* @param[in] tgt For solicited advertisements, the Target Address field
* in the neighbor solicitaton.
* For and unsolicited advertisement, the address whose
* link-layer address has changed.
* MUST NOT be multicast.
* @param[in] options Options to append to the neighbor advertisement.
*
* @return The resulting ICMPv6 packet on success.
* @return NULL, on failure.
*/
gnrc_pktsnip_t *gnrc_ndp_nbr_adv_build(uint8_t flags, ipv6_addr_t *tgt,
gnrc_pktsnip_t *options);
/**
* @brief Builds a router solicitation message for sending.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.1">
* RFC 4861, section 4.1
* </a>
*
* @param[in] options Options to append to the router solicitation.
*
* @return The resulting ICMPv6 packet on success.
* @return NULL, on failure.
*/
gnrc_pktsnip_t *gnrc_ndp_rtr_sol_build(gnrc_pktsnip_t *options);
/**
* @brief Builds a router solicitation message for sending.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.1">
* RFC 4861, section 4.1
* </a>
*
* @param[in] options Options to append to the router solicitation.
*
* @return The resulting ICMPv6 packet on success.
* @return NULL, on failure.
*/
gnrc_pktsnip_t *gnrc_ndp_rtr_sol_build(gnrc_pktsnip_t *options);
#if (defined(MODULE_GNRC_NDP_ROUTER) || defined(MODULE_GNRC_SIXLOWPAN_ND_ROUTER))
/**
* @brief Builds a router advertisement message for sending.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.2">
* RFC 4861, section 4.2
* </a>
*
* @note The source address for the packet MUST be the link-local address
* of the interface.
*
* @param[in] cur_hl Default hop limit for outgoing IP packets, 0 if
* unspecified by this router.
* @param[in] flags Flags as defined above.
* @ref NDP_RTR_ADV_FLAGS_M == 1 indicates, that the
* addresses are managed by DHCPv6,
* @ref NDP_RTR_ADV_FLAGS_O == 1 indicates that other
* configuration information is available via DHCPv6.
* @param[in] ltime Lifetime of the default router in seconds.
* @param[in] reach_time Time in milliseconds a node should assume a neighbor
* reachable. 0 means unspecified by the router.
* @param[in] retrans_timer Time in milliseconds between retransmitted
* neighbor solicitations. 0 means unspecified by
* the router.
* @param[in] options Options to append to the router advertisement.
*
* @return The resulting ICMPv6 packet on success.
* @return NULL, on failure.
*/
gnrc_pktsnip_t *gnrc_ndp_rtr_adv_build(uint8_t cur_hl, uint8_t flags, uint16_t ltime,
uint32_t reach_time, uint32_t retrans_timer,
gnrc_pktsnip_t *options);
#else
/**
* @brief A host *must not* send router advertisements at any time (so why build them?)
* @see <a href="https://tools.ietf.org/html/rfc4861#section-6.3.4">
* RFC 4861, section 6.3.4
* </a>
*
* This macro is primarily an optimization to not go into the function defined
* above.
*/
#define gnrc_ndp_rtr_adv_build(cur_hl, flags, ltime, reach_time, retrans_timer, options) (NULL)
#endif
/**
* @brief Builds a generic NDP option.
*
* @param[in] type Type of the option.
* @param[in] size Size in byte of the option (will be rounded up to the next
* multiple of 8).
* @param[in] next More options in the packet. NULL, if there are none.
*
* @return The packet snip list of options, on success
* @return NULL, if packet buffer is full
*/
gnrc_pktsnip_t *gnrc_ndp_opt_build(uint8_t type, size_t size, gnrc_pktsnip_t *next);
/**
* @brief Builds the source link-layer address option.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.6.1">
* RFC 4861, section 4.6.1
* </a>
*
* @note Must only be used with neighbor solicitations, router solicitations,
* and router advertisements. This is not checked however, since
* hosts should silently ignore it in other NDP messages.
*
* @param[in] l2addr A link-layer address of variable length.
* @param[in] l2addr_len Length of @p l2addr.
* @param[in] next More options in the packet. NULL, if there are none.
*
* @return The packet snip list of options, on success
* @return NULL, if packet buffer is full
*/
gnrc_pktsnip_t *gnrc_ndp_opt_sl2a_build(const uint8_t *l2addr, uint8_t l2addr_len,
gnrc_pktsnip_t *next);
/**
* @brief Builds the target link-layer address option.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.6.1">
* RFC 4861, section 4.6.1
* </a>
*
* @note Must only be used with neighbor advertisemnents and redirect packets.
* This is not checked however, since hosts should silently ignore it
* in other NDP messages.
*
* @param[in] l2addr A link-layer address of variable length.
* @param[in] l2addr_len Length of @p l2addr.
* @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_ndp_opt_tl2a_build(const uint8_t *l2addr, uint8_t l2addr_len,
gnrc_pktsnip_t *next);
#if (defined(MODULE_GNRC_NDP_ROUTER) || defined(MODULE_GNRC_SIXLOWPAN_ND_ROUTER))
/**
* @brief Builds the prefix information option.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.6.2">
* RFC 4861, section 4.6.2
* </a>
*
* @note Must only be used with router advertisemnents. This is not checked
* however, since nodes should silently ignore it in other NDP messages.
*
* @param[in] prefix_len The length of @p prefix in bits. Must be between
* 0 and 128.
* @param[in] flags Flags as defined above.
* @ref NDP_OPT_PI_FLAGS_L == 1 indicates, that
* @p prefix can be used for on-link determination,
* @ref NDP_OPT_PI_FLAGS_A == 1 indicates, that
* @p prefix can be used for stateless address
* configuration.
* @param[in] valid_ltime Length of time in seconds that @p prefix is valid.
* UINT32_MAX represents infinity.
* @param[in] pref_ltime Length of time in seconds that addresses using
* @p prefix remain prefered. UINT32_MAX represents
* infinity.
* @param[in] prefix An IPv6 address or a prefix of an IPv6 address.
* @param[in] next More options in the packet. NULL, if there are none.
*
* @return The packet snip list of options, on success
* @return NULL, if packet buffer is full
*/
gnrc_pktsnip_t *gnrc_ndp_opt_pi_build(uint8_t prefix_len, uint8_t flags,
uint32_t valid_ltime, uint32_t pref_ltime,
ipv6_addr_t *prefix, gnrc_pktsnip_t *next);
/**
* @brief Builds the MTU option.
*
* @see <a href="https://tools.ietf.org/html/rfc4861#section-4.6.4">
* RFC 4861, section 4.6.4
* </a>
*
* @note Must only be used with router advertisemnents. This is not checked
* however, since nodes should silently ignore it in other NDP messages.
*
* @param[in] mtu The recommended MTU for the link.
* @param[in] next More options in the packet. NULL, if there are none.
*
* @return The packet snip list of options, on success
* @return NULL, if packet buffer is full
*/
gnrc_pktsnip_t *gnrc_ndp_opt_mtu_build(uint32_t mtu, gnrc_pktsnip_t *next);
#else
/**
* @brief A host *must not* send router advertisements at any time (so why build their options?)
* @see <a href="https://tools.ietf.org/html/rfc4861#section-6.3.4">
* RFC 4861, section 6.3.4
* </a>
*
* This macro is primarily an optimization to not go into the function defined
* above.
*/
#define gnrc_ndp_opt_pi_build(prefix_len, flags, valid_ltime, pref_ltime, prefix, next) (NULL)
/**
* @brief A host *must not* send router advertisements at any time (so why build their options?)
* @see <a href="https://tools.ietf.org/html/rfc4861#section-6.3.4">
* RFC 4861, section 6.3.4
* </a>
*
* This macro is primarily an optimization to not go into the function defined
* above.
*/
#define gnrc_ndp_opt_mtu_build(mtu, next) (NULL)
#endif
#ifdef __cplusplus
}
#endif
#endif /* GNRC_NDP_H_ */
/**
* @}
*/