nd6.h File Reference

Neighbor discovery and stateless address autoconfiguration for IPv6.

Aims to be compliant with RFC 4861 (Neighbor discovery) and RFC 4862 (Address autoconfiguration).

#include "lwip/opt.h"
#include "lwip/pbuf.h"
#include "lwip/ip6.h"
#include "lwip/ip6_addr.h"
#include "lwip/netif.h"

Data Structures
struct	lladdr_option
struct	mtu_option
struct	na_header
	Neighbor advertisement message header. More...
struct	nd6_destination_cache_entry
struct	nd6_neighbor_cache_entry
struct	nd6_prefix_list_entry
struct	nd6_q_entry
	struct for queueing outgoing packets for unknown address defined here to be accessed by memp.h More...
struct	nd6_router_list_entry
struct	ns_header
	Neighbor solicitation message header. More...
struct	prefix_option
struct	ra_header
struct	redirect_header
	Redirect message header. More...
struct	redirected_header_option
struct	route_option
struct	rs_header
	Router solicitation message header. More...

Macros
#define	ND6_FLAG_OVERRIDE   (0x20)
#define	ND6_FLAG_ROUTER   (0x80)
#define	ND6_FLAG_SOLICITED   (0x40)
#define	nd6_init()   /* TODO should we init tables? */
#define	ND6_OPTION_TYPE_MTU   (0x05)
	MTU option. More...
#define	ND6_OPTION_TYPE_PREFIX_INFO   (0x03)
	Prefix information option. More...
#define	ND6_OPTION_TYPE_REDIR_HDR   (0x04)
	Redirected header option. More...
#define	ND6_OPTION_TYPE_ROUTE_INFO   (24)
	Route information option. More...
#define	ND6_OPTION_TYPE_SOURCE_LLADDR   (0x01)
	Link-layer address option. More...
#define	ND6_OPTION_TYPE_TARGET_LLADDR   (0x02)
#define	ND6_PREFIX_AUTOCONFIG_ADDRESS_DUPLICATE   0x04
#define	ND6_PREFIX_AUTOCONFIG_ADDRESS_GENERATED   0x02
#define	ND6_PREFIX_AUTOCONFIG_AUTONOMOUS   0x01
#define	ND6_PREFIX_FLAG_AUTONOMOUS   (0x40)
#define	ND6_PREFIX_FLAG_ON_LINK   (0x80)
#define	ND6_PREFIX_FLAG_ROUTER_ADDRESS   (0x20)
#define	ND6_PREFIX_FLAG_SITE_PREFIX   (0x10)
#define	ND6_RA_FLAG_HOME_AGENT   (0x20)
#define	ND6_RA_FLAG_MANAGED_ADDR_CONFIG   (0x80)
	Router advertisement message header. More...
#define	ND6_RA_FLAG_OTHER_STATEFUL_CONFIG   (0x40)
#define	ND6_RA_PREFERENCE_DISABLED   (0x10)
#define	ND6_RA_PREFERENCE_HIGH   (0x08)
#define	ND6_RA_PREFERENCE_LOW   (0x18)
#define	ND6_RA_PREFERENCE_MASK   (0x18)
#define	ND6_RA_PREFERENCE_MEDIUM   (0x00)
#define	ND6_TMR_INTERVAL   1000
	1 second period More...

Enumerations
enum	nd6_neighbor_cache_entry_state {   ND6_NO_ENTRY = 0,   ND6_INCOMPLETE,   ND6_REACHABLE,   ND6_STALE,   ND6_DELAY,   ND6_PROBE }

Functions
u16_t	nd6_get_destination_mtu (ip6_addr_t *ip6addr, struct netif *netif)
	Get the Path MTU for a destination. More...
s8_t	nd6_get_next_hop_entry (ip6_addr_t *ip6addr, struct netif *netif)
	Determine the next hop for a destination. More...
void	nd6_input (struct pbuf *p, struct netif *inp)
	Process an incoming neighbor discovery message. More...
err_t	nd6_queue_packet (s8_t neighbor_index, struct pbuf *p)
	Queue a packet for a neighbor. More...
void	nd6_reachability_hint (ip6_addr_t *ip6addr)
	Provide the Neighbor discovery process with a hint that a destination is reachable. More...
s8_t	nd6_select_router (ip6_addr_t *ip6addr, struct netif *netif)
	Select a default router for a destination. More...
void	nd6_tmr (void)
	Periodic timer for Neighbor discovery functions: More...

Variables
struct nd6_router_list_entry	default_router_list []
struct nd6_destination_cache_entry	destination_cache []
struct nd6_neighbor_cache_entry	neighbor_cache []
PACK_STRUCT_BEGIN struct ns_header	PACK_STRUCT_STRUCT
struct nd6_prefix_list_entry	prefix_list []
u32_t	reachable_time
u32_t	retrans_timer

#define ND6_FLAG_OVERRIDE   (0x20)

Referenced by nd6_input().

#define ND6_FLAG_ROUTER   (0x80)

#define ND6_FLAG_SOLICITED   (0x40)

Referenced by nd6_input().

#define nd6_init

(

)

/* TODO should we init tables? */

Referenced by lwip_init().

#define ND6_OPTION_TYPE_MTU   (0x05)

MTU option.

Referenced by nd6_input().

#define ND6_OPTION_TYPE_PREFIX_INFO   (0x03)

Prefix information option.

Referenced by nd6_input().

#define ND6_OPTION_TYPE_REDIR_HDR   (0x04)

Redirected header option.

#define ND6_OPTION_TYPE_ROUTE_INFO   (24)

Route information option.

Referenced by nd6_input().

#define ND6_OPTION_TYPE_SOURCE_LLADDR   (0x01)

Link-layer address option.

Referenced by nd6_input(), nd6_send_ns(), and nd6_send_rs().

#define ND6_OPTION_TYPE_TARGET_LLADDR   (0x02)

Referenced by nd6_input(), and nd6_send_na().

#define ND6_PREFIX_AUTOCONFIG_ADDRESS_DUPLICATE   0x04

Referenced by nd6_input().

#define ND6_PREFIX_AUTOCONFIG_ADDRESS_GENERATED   0x02

Referenced by nd6_tmr().

#define ND6_PREFIX_AUTOCONFIG_AUTONOMOUS   0x01

Referenced by nd6_input(), and nd6_tmr().

#define ND6_PREFIX_FLAG_AUTONOMOUS   (0x40)

Referenced by nd6_input().

#define ND6_PREFIX_FLAG_ON_LINK   (0x80)

Referenced by nd6_input().

#define ND6_PREFIX_FLAG_ROUTER_ADDRESS   (0x20)

#define ND6_PREFIX_FLAG_SITE_PREFIX   (0x10)

#define ND6_RA_FLAG_HOME_AGENT   (0x20)

#define ND6_RA_FLAG_MANAGED_ADDR_CONFIG   (0x80)

Router advertisement message header.

#define ND6_RA_FLAG_OTHER_STATEFUL_CONFIG   (0x40)

#define ND6_RA_PREFERENCE_DISABLED   (0x10)

#define ND6_RA_PREFERENCE_HIGH   (0x08)

#define ND6_RA_PREFERENCE_LOW   (0x18)

#define ND6_RA_PREFERENCE_MASK   (0x18)

#define ND6_RA_PREFERENCE_MEDIUM   (0x00)

#define ND6_TMR_INTERVAL   1000

1 second period

Referenced by nd6_timer(), nd6_tmr(), and sys_timeouts_init().

enum nd6_neighbor_cache_entry_state

Enumerator
ND6_NO_ENTRY
ND6_INCOMPLETE
ND6_REACHABLE
ND6_STALE
ND6_DELAY
ND6_PROBE

u16_t nd6_get_destination_mtu	(	ip6_addr_t *	ip6addr,
		struct netif *	netif
	)

Get the Path MTU for a destination.

Parameters

ip6addr	the destination address
netif	the netif on which the packet will be sent

Returns

the Path MTU, if known, or the netif default MTU

References destination_cache, netif::mtu, nd6_find_destination_cache_entry(), NULL, and nd6_destination_cache_entry::pmtu.

Referenced by ip6_output_if_src(), and tcp_eff_send_mss_impl().

s8_t nd6_get_next_hop_entry	(	ip6_addr_t *	ip6addr,
		struct netif *	netif
	)

Determine the next hop for a destination.

Will determine if the destination is on-link, else a suitable on-link router is selected.

The last entry index is cached for fast entry search.

Parameters

ip6addr	the destination address
netif	the netif on which the packet will be sent

Returns

the neighbor cache entry for the next hop, ERR_RTE if no suitable next hop was found, ERR_MEM if no cache entry could be created

References nd6_destination_cache_entry::age, nd6_neighbor_cache_entry::counter, default_router_list, destination_cache, ERR_MEM, ERR_RTE, ip6_addr_cmp, ip6_addr_copy, ip6_addr_islinklocal, ip6_addr_set, ip6_addr_set_any, nd6_neighbor_cache_entry::isrouter, netif::mtu, nd6_cached_destination_index, nd6_cached_neighbor_index, nd6_find_destination_cache_entry(), nd6_find_neighbor_cache_entry(), ND6_INCOMPLETE, nd6_is_prefix_in_netif(), nd6_new_destination_cache_entry(), nd6_new_neighbor_cache_entry(), nd6_select_router(), ND6_STATS_INC, neighbor_cache, nd6_neighbor_cache_entry::netif, NULL, nd6_destination_cache_entry::pmtu, nd6_neighbor_cache_entry::probes_sent, and nd6_neighbor_cache_entry::state.

Referenced by ethip6_output().

void nd6_input	(	struct pbuf *	p,
		struct netif *	inp
	)

Process an incoming neighbor discovery message.

Parameters

p	the nd packet, p->payload pointing to the icmpv6 header
inp	the netif on which this packet was received

References buffer, nd6_neighbor_cache_entry::counter, default_router_list, nd6_neighbor_cache_entry::delay_time, destination_cache, nd6_prefix_list_entry::flags, nd6_router_list_entry::flags, netif::hwaddr_len, ICMP6_TYPE_NA, ICMP6_TYPE_NS, ICMP6_TYPE_PTB, ICMP6_TYPE_RA, ICMP6_TYPE_RD, if(), nd6_prefix_list_entry::invalidation_timer, nd6_router_list_entry::invalidation_timer, ip6_addr_cmp, IP6_ADDR_INVALID, ip6_addr_isany, ip6_addr_islinklocal, ip6_addr_ismulticast, ip6_addr_istentative, ip6_addr_isvalid, ip6_addr_set, ip6_addr_set_solicitednode, ip6_current_dest_addr, ip6_current_src_addr, IP6_HLEN, pbuf::len, mld6_leavegroup(), netif::mtu, multicast_address, ND6_DELAY, nd6_find_destination_cache_entry(), nd6_find_neighbor_cache_entry(), ND6_FLAG_OVERRIDE, ND6_FLAG_SOLICITED, nd6_get_onlink_prefix(), nd6_get_router(), ND6_INCOMPLETE, nd6_new_neighbor_cache_entry(), nd6_new_onlink_prefix(), nd6_new_router(), ND6_OPTION_TYPE_MTU, ND6_OPTION_TYPE_PREFIX_INFO, ND6_OPTION_TYPE_ROUTE_INFO, ND6_OPTION_TYPE_SOURCE_LLADDR, ND6_OPTION_TYPE_TARGET_LLADDR, ND6_PREFIX_AUTOCONFIG_ADDRESS_DUPLICATE, ND6_PREFIX_AUTOCONFIG_AUTONOMOUS, ND6_PREFIX_FLAG_AUTONOMOUS, ND6_PREFIX_FLAG_ON_LINK, nd6_ra_buffer, ND6_REACHABLE, ND6_SEND_FLAG_ALLNODES_DEST, nd6_send_na(), nd6_send_q(), ND6_STATS_INC, neighbor_cache, nd6_router_list_entry::neighbor_entry, nd6_neighbor_cache_entry::netif, netif_ip6_addr, netif_ip6_addr_set_state, netif_ip6_addr_state, NULL, pbuf::payload, pbuf_copy_partial(), pbuf_free(), nd6_destination_cache_entry::pmtu, prefix_list, reachable_time, nd6_neighbor_cache_entry::reachable_time, retrans_timer, netif::rs_count, nd6_neighbor_cache_entry::state, and pbuf::tot_len.

Referenced by icmp6_input().

err_t nd6_queue_packet	(	s8_t	neighbor_index,
		struct pbuf *	q
	)

Queue a packet for a neighbor.

Parameters

neighbor_index	the index in the neighbor cache table
q	packet to be queued

Returns

ERR_OK if succeeded, ERR_MEM if out of memory

References ERR_ARG, ERR_MEM, ERR_OK, LWIP_DBG_TRACE, LWIP_DEBUGF, memp_malloc(), nd6_free_q(), neighbor_cache, pbuf::next, nd6_q_entry::next, NULL, nd6_q_entry::p, pbuf_alloc(), pbuf_copy(), pbuf_free(), PBUF_LINK, PBUF_RAM, pbuf_ref(), PBUF_ROM, nd6_neighbor_cache_entry::q, S16_F, pbuf::tot_len, and pbuf::type.

Referenced by ethip6_output().

void nd6_reachability_hint

(

ip6_addr_t *

ip6addr

)

Provide the Neighbor discovery process with a hint that a destination is reachable.

Called by tcp_receive when ACKs are received or sent (as per RFC). This is useful to avoid sending NS messages every 30 seconds.

Parameters

ip6addr

the destination address which is know to be reachable by an upper layer protocol (TCP)

References nd6_neighbor_cache_entry::counter, destination_cache, ip6_addr_cmp, nd6_cached_destination_index, nd6_cached_neighbor_index, nd6_find_destination_cache_entry(), nd6_find_neighbor_cache_entry(), ND6_REACHABLE, ND6_STATS_INC, neighbor_cache, reachable_time, nd6_neighbor_cache_entry::reachable_time, and nd6_neighbor_cache_entry::state.

Referenced by tcp_receive().

s8_t nd6_select_router	(	ip6_addr_t *	ip6addr,
		struct netif *	netif
	)

Select a default router for a destination.

Parameters

ip6addr	the destination address
netif	the netif for the outgoing packet, if known

Returns

the default router entry index, or -1 if no suitable router is found

References default_router_list, ND6_REACHABLE, nd6_router_list_entry::neighbor_entry, nd6_neighbor_cache_entry::netif, NULL, nd6_neighbor_cache_entry::state, and void.

Referenced by ip6_route(), and nd6_get_next_hop_entry().

void nd6_tmr

(

void

)

Periodic timer for Neighbor discovery functions:

• Update neighbor reachability states
• Update destination cache entries age
• Update invalidation timers of default routers and on-link prefixes
• Perform duplicate address detection (DAD) for our addresses
• Send router solicitations

References nd6_destination_cache_entry::age, nd6_neighbor_cache_entry::counter, default_router_list, nd6_neighbor_cache_entry::delay_time, destination_cache, nd6_prefix_list_entry::flags, nd6_router_list_entry::flags, netif::flags, nd6_prefix_list_entry::invalidation_timer, nd6_router_list_entry::invalidation_timer, netif::ip6_addr, IP6_ADDR_INVALID, ip6_addr_istentative, IP6_ADDR_PREFERRED, ip6_addr_set_solicitednode, netif::ip6_addr_state, IP6_ADDR_TENTATIVE, netif::ip6_autoconfig_enabled, nd6_neighbor_cache_entry::isrouter, mld6_joingroup(), multicast_address, ND6_DELAY, nd6_free_neighbor_cache_entry(), ND6_INCOMPLETE, ND6_NO_ENTRY, ND6_PREFIX_AUTOCONFIG_ADDRESS_GENERATED, ND6_PREFIX_AUTOCONFIG_AUTONOMOUS, ND6_PROBE, ND6_REACHABLE, ND6_SEND_FLAG_MULTICAST_DEST, nd6_send_ns(), nd6_send_q(), nd6_send_rs(), ND6_STALE, ND6_TMR_INTERVAL, neighbor_cache, nd6_router_list_entry::neighbor_entry, nd6_prefix_list_entry::netif, NETIF_FLAG_UP, netif_ip6_addr, netif_ip6_addr_set_state, netif_ip6_addr_state, netif_list, netif::next, NULL, nd6_prefix_list_entry::prefix, prefix_list, nd6_neighbor_cache_entry::probes_sent, nd6_neighbor_cache_entry::reachable_time, netif::rs_count, nd6_neighbor_cache_entry::stale_time, nd6_neighbor_cache_entry::state, and netif::state.

Referenced by nd6_timer().

struct nd6_router_list_entry default_router_list[]

Referenced by ip6_route(), nd6_get_next_hop_entry(), nd6_get_router(), nd6_input(), nd6_new_router(), nd6_select_router(), and nd6_tmr().

struct nd6_destination_cache_entry destination_cache[]

Referenced by nd6_find_destination_cache_entry(), nd6_get_destination_mtu(), nd6_get_next_hop_entry(), nd6_input(), nd6_new_destination_cache_entry(), nd6_reachability_hint(), and nd6_tmr().

struct nd6_neighbor_cache_entry neighbor_cache[]

Referenced by ethip6_output(), nd6_find_neighbor_cache_entry(), nd6_free_neighbor_cache_entry(), nd6_get_next_hop_entry(), nd6_input(), nd6_new_neighbor_cache_entry(), nd6_new_router(), nd6_queue_packet(), nd6_reachability_hint(), nd6_send_q(), and nd6_tmr().

PACK_STRUCT_BEGIN struct route_option PACK_STRUCT_STRUCT

struct nd6_prefix_list_entry prefix_list[]

Referenced by nd6_get_onlink_prefix(), nd6_input(), nd6_is_prefix_in_netif(), nd6_new_onlink_prefix(), and nd6_tmr().

u32_t reachable_time

Referenced by nd6_input(), and nd6_reachability_hint().

u32_t retrans_timer

Referenced by nd6_input().