uIP IPv6 specific features
[The uIP TCP/IP stack]

The uIP IPv6 stack provides new Internet communication abilities to Contiki. More...

Data Structures
struct	uip_ds6_nbr
	An entry in the nbr cache. More...
struct	uip_ds6_defrt
	An entry in the default router list. More...
struct	uip_ds6_prefix
	A prefix list entry. More...
struct	uip_ds6_addr
	* More...
struct	uip_ds6_aaddr
	Anycast address. More...
struct	uip_ds6_maddr
	A multicast address. More...
struct	uip_ds6_route
	An entry in the routing table. More...
struct	uip_ds6_netif
	Interface structure (contains all the interface variables). More...
struct	uip_ds6_element
	Generic type for a DS6, to use a common loop though all DS. More...
struct	uip_icmp6_error
	ICMPv6 Error message constant part. More...
struct	uip_nd6_neighbor
	An entry in the neighbor cache. More...
struct	uip_nd6_defrouter
	An entry in the default router list. More...
struct	uip_nd6_prefix
	A prefix list entry. More...
struct	uip_nd6_ns
	A neighbor solicitation constant part. More...
struct	uip_nd6_na
	A neighbor advertisement constant part. More...
struct	uip_nd6_rs
	A router solicitation constant part. More...
struct	uip_nd6_ra
	A router advertisement constant part. More...
struct	uip_nd6_redirect
	A redirect message constant part. More...
struct	uip_nd6_opt_hdr
	ND option header. More...
struct	uip_nd6_opt_prefix_info
	ND option prefix information. More...
struct	uip_nd6_opt_mtu
	ND option MTU. More...
Files
file	uip-ds6.c
	IPv6 data structures handling functions Comprises part of the Neighbor discovery (RFC 4861) and auto configuration (RFC 4862 )state machines.
file	uip-ds6.h
	Network interface and stateless autoconfiguration (RFC 4862).
file	uip-icmp6.c
	ICMPv6 echo request and error messages (RFC 4443).
file	uip-icmp6.h
	ICMPv6 echo request and error messages (RFC 4443).
file	uip-nd6.c
	Neighbor discovery (RFC 4861).
file	uip-nd6.h
	Neighbor discovery (RFC 4861).
file	uip6.c
	The uIP TCP/IPv6 stack code.
file	rpl-dag.c
	Logic for Directed Acyclic Graphs in RPL.
file	rpl-icmp6.c
	ICMP6 I/O for RPL control messages.
file	rpl-of-etx.c
	The minrank-hysteresis objective function (OCP 1).
file	rpl-of0.c
	An implementation of RPL's objective function 0.
file	rpl-timers.c
	RPL timer management.
file	rpl.c
	ContikiRPL, an implementation of IETF ROLL RPL.
Defines
#define	UIP_DS6_NBR_NBS 0
	Configuration.
#define	NBR_INCOMPLETE 0
	Possible states for the nbr cache entries.
#define	ADDR_TENTATIVE 0
	Possible states for the an address (RFC 4862).
#define	ADDR_ANYTYPE 0
	How the address was acquired: Autoconf, DHCP or manually.
#define	UIP_DS6_PERIOD (CLOCK_SECOND/10)
	General DS6 definitions.
#define	UIP_DS6_ROUTE_STATE_TYPE rpl_route_entry_t
	define some additional RPL related route state and neighbor callback for RPL - if not a DS6_ROUTE_STATE is already set
#define	UIP_ICMP6_ECHO_REQUEST_LEN 4
	Echo Request constant part length.
#define	UIP_ICMP6_ERROR_LEN 4
	ICMPv6 Error message constant part length.
#define	UIP_ND6_OPT_HDR_BUF ((uip_nd6_opt_hdr *)&uip_buf[uip_l2_l3_icmp_hdr_len + nd6_opt_offset])
	Pointer to ND option.
Typedefs
typedef struct uip_ds6_nbr	uip_ds6_nbr_t
	An entry in the nbr cache.
typedef struct uip_ds6_defrt	uip_ds6_defrt_t
	An entry in the default router list.
typedef struct uip_ds6_prefix	uip_ds6_prefix_t
	A prefix list entry.
typedef struct uip_ds6_addr	uip_ds6_addr_t
	*
typedef struct uip_ds6_aaddr	uip_ds6_aaddr_t
	Anycast address.
typedef struct uip_ds6_maddr	uip_ds6_maddr_t
	A multicast address.
typedef struct uip_ds6_route	uip_ds6_route_t
	An entry in the routing table.
typedef struct uip_ds6_netif	uip_ds6_netif_t
	Interface structure (contains all the interface variables).
typedef struct uip_ds6_element	uip_ds6_element_t
	Generic type for a DS6, to use a common loop though all DS.
Enumerations
enum	uip_neighbor_state
	Possible states for the neighbor cache entries. More...
Functions
void	uip_ds6_init (void)
	Initialize data structures.
void	uip_ds6_periodic (void)
	Periodic processing of data structures.
uint8_t	uip_ds6_list_loop (uip_ds6_element_t list, uint8_t size, uint16_t elementsize, uip_ipaddr_t ipaddr, uint8_t ipaddrlen, uip_ds6_element_t **out_element)
	Generic loop routine on an abstract data structure, which generalizes all data structures used in DS6.
void	uip_ds6_select_src (uip_ipaddr_t src, uip_ipaddr_t dst)
	Source address selection, see RFC 3484.
void	uip_ds6_set_addr_iid (uip_ipaddr_t ipaddr, uip_lladdr_t lladdr)
	set the last 64 bits of an IP address based on the MAC address
uint8_t	get_match_length (uip_ipaddr_t src, uip_ipaddr_t dst)
	Get the number of matching bits of two addresses.
void	uip_ds6_dad (uip_ds6_addr_t *ifaddr)
	Perform Duplicate Address Selection on one address.
int	uip_ds6_dad_failed (uip_ds6_addr_t *ifaddr)
	Callback when DAD failed.
void	uip_ds6_send_rs (void)
	Send periodic RS to find router.
uint32_t	uip_ds6_compute_reachable_time (void)
	Compute the reachable time based on base reachable time, see RFC 4861.
u16_t	uip_chksum (u16_t *data, u16_t len)
	Calculate the Internet checksum over a buffer.
u16_t	uip_ipchksum (void)
	Calculate the IP header checksum of the packet header in uip_buf.
u16_t	uip_icmp6chksum (void)
	Calculate the ICMP checksum of the packet in uip_buf.
void	uip_init (void)
	uIP initialization function.
struct uip_udp_conn *	uip_udp_new (const uip_ipaddr_t *ripaddr, u16_t rport)
	Set up a new UDP connection.
void	uip_process (u8_t flag)
u16_t	uip_htons (u16_t val)
	Convert 16-bit quantity from host byte order to network byte order.
void	uip_send (const void *data, int len)
	Send data on the current connection.
Variables
struct etimer	uip_ds6_timer_rs
	Timer for maintenance of data structures.
uip_ds6_netif_t	uip_ds6_if
struct etimer	uip_ds6_timer_rs
	Timer for maintenance of data structures.
uip_ds6_route_t	uip_ds6_routing_table [UIP_DS6_ROUTE_NB]
	Prefix list.
"DS6" Data structures
number of rs already sent
uip_ds6_netif_t	uip_ds6_if
uip_ds6_nbr_t	uip_ds6_nbr_cache [UIP_DS6_NBR_NB]
	The single interface.
uip_ds6_defrt_t	uip_ds6_defrt_list [UIP_DS6_DEFRT_NB]
	Neighor cache.
uip_ds6_prefix_t	uip_ds6_prefix_list [UIP_DS6_PREFIX_NB]
	Default rt list.
uip_ds6_route_t	uip_ds6_routing_table [UIP_DS6_ROUTE_NB]
	Prefix list.
Layer 2 variables

uip_lladdr_t	uip_lladdr = {{0x00,0x06,0x98,0x00,0x02,0x32}}
	Host L2 address.
Layer 3 variables

u8_t *	uip_next_hdr
	Type of the next header in IPv6 header or extension headers.
u8_t	uip_ext_bitmap = 0
	bitmap we use to record which IPv6 headers we have already seen
u8_t	uip_ext_len = 0
	length of the extension headers read.
u8_t	uip_ext_opt_offset = 0
	length of the header options read
Buffer variables

uip_buf_t	uip_aligned_buf
	Packet buffer for incoming and outgoing packets.
void *	uip_appdata
	Pointer to the application data in the packet buffer.
void *	uip_sappdata
u16_t	uip_len
	The length of the packet in the uip_buf buffer.
u16_t	uip_slen
General variables

u8_t	uip_flags
struct uip_conn *	uip_conn
	Pointer to the current TCP connection.
UDP variables

struct uip_udp_conn *	uip_udp_conn
	The current UDP connection.
struct uip_udp_conn	uip_udp_conns [UIP_UDP_CONNS]
Neighbor Cache basic routines

uip_ds6_nbr_t *	uip_ds6_nbr_add (uip_ipaddr_t ipaddr, uip_lladdr_t lladdr, uint8_t isrouter, uint8_t state)
void	uip_ds6_nbr_rm (uip_ds6_nbr_t *nbr)
uip_ds6_nbr_t *	uip_ds6_nbr_lookup (uip_ipaddr_t *ipaddr)
Default router list basic routines

uip_ds6_defrt_t *	uip_ds6_defrt_add (uip_ipaddr_t *ipaddr, unsigned long interval)
void	uip_ds6_defrt_rm (uip_ds6_defrt_t *defrt)
uip_ds6_defrt_t *	uip_ds6_defrt_lookup (uip_ipaddr_t *ipaddr)
uip_ipaddr_t *	uip_ds6_defrt_choose (void)
Prefix list basic routines

uip_ds6_prefix_t *	uip_ds6_prefix_add (uip_ipaddr_t *ipaddr, uint8_t ipaddrlen, unsigned long interval)
void	uip_ds6_prefix_rm (uip_ds6_prefix_t *prefix)
uip_ds6_prefix_t *	uip_ds6_prefix_lookup (uip_ipaddr_t *ipaddr, uint8_t ipaddrlen)
uint8_t	uip_ds6_is_addr_onlink (uip_ipaddr_t *ipaddr)
Unicast address list basic routines

uip_ds6_addr_t *	uip_ds6_addr_add (uip_ipaddr_t *ipaddr, unsigned long vlifetime, uint8_t type)
void	uip_ds6_addr_rm (uip_ds6_addr_t *addr)
uip_ds6_addr_t *	uip_ds6_addr_lookup (uip_ipaddr_t *ipaddr)
uip_ds6_addr_t *	uip_ds6_get_link_local (int8_t state)
uip_ds6_addr_t *	uip_ds6_get_global (int8_t state)
Multicast address list basic routines

uip_ds6_maddr_t *	uip_ds6_maddr_add (uip_ipaddr_t *ipaddr)
void	uip_ds6_maddr_rm (uip_ds6_maddr_t *maddr)
uip_ds6_maddr_t *	uip_ds6_maddr_lookup (uip_ipaddr_t *ipaddr)
Anycast address list basic routines

uip_ds6_aaddr_t *	uip_ds6_aaddr_add (uip_ipaddr_t *ipaddr)
void	uip_ds6_aaddr_rm (uip_ds6_aaddr_t *aaddr)
uip_ds6_aaddr_t *	uip_ds6_aaddr_lookup (uip_ipaddr_t *ipaddr)
Routing Table basic routines

uip_ds6_route_t *	uip_ds6_route_lookup (uip_ipaddr_t *destipaddr)
uip_ds6_route_t *	uip_ds6_route_add (uip_ipaddr_t ipaddr, uint8_t length, uip_ipaddr_t nexthop, uint8_t metric)
void	uip_ds6_route_rm (uip_ds6_route_t *route)
void	uip_ds6_route_rm_by_nexthop (uip_ipaddr_t *nexthop)
ICMPv6 RFC4443 Message processing and sending

void	uip_icmp6_echo_request_input (void)
	\ brief Process an echo request
void	uip_icmp6_error_output (u8_t type, u8_t code, u32_t param)
	Send an icmpv6 error message.
void	uip_icmp6_send (uip_ipaddr_t *dest, int type, int code, int payload_len)
	Send an icmpv6 message.
ND Neighbor Cache, Router List and Prefix List handling functions

void	uip_nd6_init (void)
	Initialize Neighbor Discovery structures.
void	uip_nd6_periodic (void)
	Periodic processing of Neighbor Discovery Structures.
struct uip_nd6_neighbor *	uip_nd6_nbrcache_lookup (uip_ipaddr_t *ipaddr)
	Look for a neighbor cache entry corresponding to a specific IP address.
struct uip_nd6_neighbor *	uip_nd6_nbrcache_add (uip_ipaddr_t ipaddr, uip_lladdr_t lladdr, u8_t isrouter, uip_neighbor_state state)
	Add a neighbor cache entry.
struct uip_nd6_defrouter *	uip_nd6_choose_defrouter (void)
	Returns a default router.
struct uip_nd6_defrouter *	uip_nd6_defrouter_lookup (struct uip_nd6_neighbor *neighbor)
	Find a default router corresponding to a given neighbor cache entry.
void	uip_nd6_defrouter_rm (struct uip_nd6_defrouter *router)
	Remove a default router.
struct uip_nd6_defrouter *	uip_nd6_defrouter_add (struct uip_nd6_neighbor *neighbor, unsigned long interval)
	Add a default router.
u8_t	uip_nd6_is_addr_onlink (uip_ipaddr_t *ipaddr)
	Check if an IP address in on-link by looking at prefix list.
struct uip_nd6_prefix *	uip_nd6_prefix_lookup (uip_ipaddr_t *ipaddr)
	Find a given prefix.
struct uip_nd6_prefix *	uip_nd6_prefix_add (uip_ipaddr_t *ipaddr, u8_t length, unsigned long interval)
	Add a prefix.
void	uip_nd6_prefix_rm (struct uip_nd6_prefix *prefix)
	Remove a prefix from th eprefix list.
ND Messages Processing and Generation

void	uip_nd6_ns_input (void)
	Process a neighbor solicitation.
void	uip_nd6_ns_output (uip_ipaddr_t src, uip_ipaddr_t dest, uip_ipaddr_t *tgt)
	Send a neighbor solicitation, send a Neighbor Advertisement.
void	uip_nd6_na_input (void)
	Process a Neighbor Advertisement.
void	uip_nd6_rs_output (void)
	Send a Router Solicitation.
void	uip_nd6_ra_input (void)
	process a Router Advertisement
Macros to check if an IP address (unicast, multicast or anycast) is mine
compute random reachable timer
#define	uip_ds6_is_my_addr(addr) (uip_ds6_addr_lookup(addr) != NULL)
#define	uip_ds6_is_my_maddr(addr) (uip_ds6_maddr_lookup(addr) != NULL)
#define	uip_ds6_is_my_aaddr(addr) (uip_ds6_aaddr_lookup(addr) != NULL)
ICMPv6 message types

#define	ICMP6_DST_UNREACH 1
	dest unreachable
#define	ICMP6_PACKET_TOO_BIG 2
	packet too big
#define	ICMP6_TIME_EXCEEDED 3
	time exceeded
#define	ICMP6_PARAM_PROB 4
	ip6 header bad
#define	ICMP6_ECHO_REQUEST 128
	Echo request.
#define	ICMP6_ECHO_REPLY 129
	Echo reply.
#define	ICMP6_RS 133
	Router Solicitation.
#define	ICMP6_RA 134
	Router Advertisement.
#define	ICMP6_NS 135
	Neighbor Solicitation.
#define	ICMP6_NA 136
	Neighbor advertisement.
#define	ICMP6_REDIRECT 137
	Redirect.
#define	ICMP6_RPL 155
	RPL.
ICMPv6 Destination Unreachable message codes

#define	ICMP6_DST_UNREACH_NOROUTE 0
	no route to destination
#define	ICMP6_DST_UNREACH_ADMIN 1
	administratively prohibited
#define	ICMP6_DST_UNREACH_NOTNEIGHBOR 2
	not a neighbor(obsolete)
#define	ICMP6_DST_UNREACH_BEYONDSCOPE 2
	beyond scope of source address
#define	ICMP6_DST_UNREACH_ADDR 3
	address unreachable
#define	ICMP6_DST_UNREACH_NOPORT 4
	port unreachable
ICMPv6 Time Exceeded message codes

#define	ICMP6_TIME_EXCEED_TRANSIT 0
	ttl==0 in transit
#define	ICMP6_TIME_EXCEED_REASSEMBLY 1
	ttl==0 in reass
ICMPv6 Parameter Problem message codes

#define	ICMP6_PARAMPROB_HEADER 0
	erroneous header field
#define	ICMP6_PARAMPROB_NEXTHEADER 1
	unrecognized next header
#define	ICMP6_PARAMPROB_OPTION 2
	unrecognized option
Pointers to the header structures.
All pointers except UIP_IP_BUF depend on uip_ext_len, which at packet reception, is the total length of the extension headers. The pointer to ND6 options header also depends on nd6_opt_offset, which we set in each function. Care should be taken when manipulating these buffers about the value of these length variables
#define	UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
	Pointer to IP header.
#define	UIP_ICMP_BUF ((struct uip_icmp_hdr *)&uip_buf[uip_l2_l3_hdr_len])
	Pointer to ICMP header.
#define	UIP_ND6_RS_BUF ((uip_nd6_rs *)&uip_buf[uip_l2_l3_icmp_hdr_len])
#define	UIP_ND6_RA_BUF ((uip_nd6_ra *)&uip_buf[uip_l2_l3_icmp_hdr_len])
#define	UIP_ND6_NS_BUF ((uip_nd6_ns *)&uip_buf[uip_l2_l3_icmp_hdr_len])
#define	UIP_ND6_NA_BUF ((uip_nd6_na *)&uip_buf[uip_l2_l3_icmp_hdr_len])
General

#define	UIP_ND6_HOP_LIMIT 255
	HOP LIMIT to be used when sending ND messages (255).
#define	UIP_ND6_INFINITE_LIFETIME 0xFFFFFFFF
	INFINITE lifetime.
Configuration options

#define	UIP_CONF_ND6_MAX_NEIGHBORS 4
	max number of entries in the neighbor cache
#define	UIP_CONF_ND6_MAX_DEFROUTERS 2
	max number of entries in the default router cache
#define	UIP_CONF_ND6_MAX_PREFIXES 2
	max number of entries in the prefix list
RFC 4861 Host constant

#define	UIP_ND6_MAX_RTR_SOLICITATION_DELAY 1
#define	UIP_ND6_RTR_SOLICITATION_INTERVAL 4
#define	UIP_ND6_MAX_RTR_SOLICITATIONS 3
RFC 4861 Router constants

#define	UIP_ND6_SEND_RA 1
#define	UIP_ND6_MAX_RA_INTERVAL 600
#define	UIP_ND6_MIN_RA_INTERVAL (UIP_ND6_MAX_RA_INTERVAL / 3)
#define	UIP_ND6_M_FLAG 0
#define	UIP_ND6_O_FLAG 0
#define	UIP_ND6_ROUTER_LIFETIME 3 * UIP_ND6_MAX_RA_INTERVAL
#define	UIP_ND6_MAX_INITIAL_RA_INTERVAL 16
#define	UIP_ND6_MAX_INITIAL_RAS 3
#define	UIP_ND6_MIN_DELAY_BETWEEN_RAS 3
#define	UIP_ND6_MAX_RA_DELAY_TIME_MS 500
RFC 4861 Node constant

#define	UIP_ND6_MAX_MULTICAST_SOLICIT 3
#define	UIP_ND6_MAX_UNICAST_SOLICIT 3
#define	UIP_ND6_REACHABLE_TIME 30000
#define	UIP_ND6_RETRANS_TIMER 1000
#define	UIP_ND6_DELAY_FIRST_PROBE_TIME 5
#define	UIP_ND6_MIN_RANDOM_FACTOR(x) (x / 2)
#define	UIP_ND6_MAX_RANDOM_FACTOR(x) ((x) + (x) / 2)
ND6 option types

#define	UIP_ND6_OPT_SLLAO 1
#define	UIP_ND6_OPT_TLLAO 2
#define	UIP_ND6_OPT_PREFIX_INFO 3
#define	UIP_ND6_OPT_REDIRECTED_HDR 4
#define	UIP_ND6_OPT_MTU 5
#define	UIP_ND6_OPT_TYPE_OFFSET 0
#define	UIP_ND6_OPT_LEN_OFFSET 1
#define	UIP_ND6_OPT_DATA_OFFSET 2
ND6 message length (excluding options)

#define	UIP_ND6_NA_LEN 20
#define	UIP_ND6_NS_LEN 20
#define	UIP_ND6_RA_LEN 12
#define	UIP_ND6_RS_LEN 4
ND6 option length in bytes

#define	UIP_ND6_OPT_HDR_LEN 2
#define	UIP_ND6_OPT_PREFIX_INFO_LEN 32
#define	UIP_ND6_OPT_MTU_LEN 8
#define	UIP_ND6_OPT_LLAO_LEN 8
	length of a ND6 LLAO option for default L2 type (e.g.
Neighbor Advertisement flags masks

#define	UIP_ND6_NA_FLAG_ROUTER 0x80
#define	UIP_ND6_NA_FLAG_SOLICITED 0x40
#define	UIP_ND6_NA_FLAG_OVERRIDE 0x20
#define	UIP_ND6_RA_FLAG_ONLINK 0x80
#define	UIP_ND6_RA_FLAG_AUTONOMOUS 0x40
Buffer defines

#define	FBUF ((struct uip_tcpip_hdr *)&uip_reassbuf[0])
#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_UDP_BUF ((struct uip_udp_hdr *)&uip_buf[uip_l2_l3_hdr_len])
#define	UIP_TCP_BUF ((struct uip_tcp_hdr *)&uip_buf[uip_l2_l3_hdr_len])
#define	UIP_EXT_BUF ((struct uip_ext_hdr *)&uip_buf[uip_l2_l3_hdr_len])
#define	UIP_ROUTING_BUF ((struct uip_routing_hdr *)&uip_buf[uip_l2_l3_hdr_len])
#define	UIP_FRAG_BUF ((struct uip_frag_hdr *)&uip_buf[uip_l2_l3_hdr_len])
#define	UIP_HBHO_BUF ((struct uip_hbho_hdr *)&uip_buf[uip_l2_l3_hdr_len])
#define	UIP_DESTO_BUF ((struct uip_desto_hdr *)&uip_buf[uip_l2_l3_hdr_len])
#define	UIP_EXT_HDR_OPT_BUF ((struct uip_ext_hdr_opt *)&uip_buf[uip_l2_l3_hdr_len + uip_ext_opt_offset])
#define	UIP_EXT_HDR_OPT_PADN_BUF ((struct uip_ext_hdr_opt_padn *)&uip_buf[uip_l2_l3_hdr_len + uip_ext_opt_offset])
#define	UIP_ICMP6_ERROR_BUF ((struct uip_icmp6_error *)&uip_buf[uip_l2_l3_icmp_hdr_len])
TCP defines

#define	TCP_FIN 0x01
#define	TCP_SYN 0x02
#define	TCP_RST 0x04
#define	TCP_PSH 0x08
#define	TCP_ACK 0x10
#define	TCP_URG 0x20
#define	TCP_CTL 0x3f
#define	TCP_OPT_END 0
#define	TCP_OPT_NOOP 1
#define	TCP_OPT_MSS 2
#define	TCP_OPT_MSS_LEN 4

Detailed Description

The uIP IPv6 stack provides new Internet communication abilities to Contiki.

This document describes Ipv6 specific features. For features that are common to the IPv4 and IPv6 code please refer to uIP.

Introduction

Ipv6 is to replace IPv4 in a near future. Indeed, to move to a real Internet of Things a larger address space is required. This extended address space (2^128 instead of 2^32) is one of the key features of IPv6 together with its simplified header format, its improved support for extensions and options, and its new QoS and security capabilities.

The uip IPv6 stack implementation targets constrained devices such as sensors. The code size is around 11.5Kbyte and the RAM usage around 1.7Kbyte (see below for more detailed information). Our implementation follows closely RFC 4294 IPv6 Node Requirements whose goal is to allow "IPv6 to function well and interoperate in a large number of situations and deployments".

The implementation currently does not support any router features (it does not forward packets, send RAs...)

IPv6 Protocol Implementation

This section gives a short overview of the different protocols that are part of the uIP IPv6 stack. A complete description can be found in the corresponding IETF standards which are available at http://www.ietf.org/rfc.html.

Note:: The UIP_CONF_IPV6 compilation flag is used to enable IPv6 (and disable IPv4). It is also recommended to set UIP_CONF_IPV6_CHECKS to 1 if one cannot guarantee that the incoming packets are correctly formed.

IPv6 (RFC 2460)

The IP packets are processed in the uip_process function. After a few validity checks on the IPv6 header, the extension headers are processed until an upper layer (ICMPv6, UDP or TCP) header is found. We support 4 extension headers:

Hop-by-Hop Options: this header is used to carry optional information that need to be examined only by a packet's destination node.
Routing: this header is used by an IPv6 source to list one or more intermediate nodes to be "visited" on the way to a packet's destination.
Fragment: this header is used when a large packet is divided into smaller fragments.
Destination Options: this header is used to carry optional information that need be examined only by a packet's destination node The Authentication and ESP headers are not currently supported.

The IPv6 header, extension headers, and options are defined in uip.h.

Although we can receive packets with the extension headers listed above, we do not offer support to send packets with extension headers.

Fragment Reassembly
This part of the code is very similar to the IPv4 fragmentation code. The only difference is that the fragmented packet is not assumed to be a TCP packet. As a result, we use a different timer to time-out reassembly if all fragments have not been received after UIP_REASS_MAXAGE = 60s.

Note:: Fragment reassembly is enabled if UIP_CONF_REASSEMBLY is set to 1.; We can only reassemble packet of at most UIP_LINK_MTU = 1280 bytes as we do not have larger buffers.

Interface and Addressing (RFC 4291, RFC 4861 p.51, RFC 4862 p.10)

An IPv6 address has 128 bits and is defined as follows:

typedef union uip_ip6addr_t {
  u8_t  u8[16]
  u16_t u16[8];
} uip_ip6addr_t;

We assume that each node has a single interface of type uip_netif.

Each interface can have up to UIP_NETIF_MAX_ADDRESSES unicast IPv6 addresses including its link-local address. It also has a solicited-node multicast address. We assume that the unicast addresses are obtained via stateless address autoconfiguration so that the solicited-node address is the same for all the unicast addresses. Indeed, the solicited-node multicast address is formed by combining the prefix FF02::1:FF00:0/104 and the last 24-bits of the corresponding IPv6 address. When using stateless address autoconfiguration these bits are always equal to the last 24-bits of the link-layer address.

Multicast support

We do not support applications using multicast. Nevertheless, our node should join the all-nodes multicast address, as well as its solicited-node multicast address. Joining the all-nodes multicast address does not require any action. Joining the solicited-node multicast address is done using Multicast Listener Discovery (MLD or MLDv2). More exactly, the node should send a MLD report packet. However this step can be safely skipped and we do so.

Neighbor Discovery (RFC 4861)

IPv6 nodes on the same link use Neighbor Discovery to discover each other's presence, to determine each other's link-layer addresses, to find routers, and to maintain reachability information about the paths to active neighbors (citation from the abstract of RFC 4861).

Note:: In IPv6 terminology, a link is a communication medium over which nodes can communicate at the link layer, i.e., the layer immediately below IP (e.g.: ethernet, 802.11, etc.). Neighbors are thus nodes attached to the same link.

Neighbor Discovery (ND) replaces ARP in IPv4 but does much more.

Neighbor discovery messages

Neighbor Solicitation (NS)
Sent by a node during duplicate address detection, address resolution or neighbor unreachability detection (see explanations below).
Possible option: Source link-layer address
Neighbor Advertisement (NA)
Sent by a node in response to a NS.
Possible option: Target link-layer address
Router Advertisement (RA)
Sent periodically by routers to advertise their presence together with various link and Internet parameters.
Possible options: Source link-layer address, MTU, Prefix Information
Router Solicitation (RS)
Sent by a host to request routers to generate a RA immediately rather than at their next scheduled time. Received RS are discarded.
Possible option: Source link-layer address
Redirect Message
Not supported

The structures corresponding to the different message headers and options are in uip-nd6.h. The functions used to send / process this messages are also described in uip-nd6.h although the actual code is in uip-nd6-io.c.

Neighbor discovery structures
We use the following neighbor discovery structures (declared in uip-nd6.c):

A neighbor cache with entries of type uip_nd6_neighbor
A prefix list with entries of type uip_nd6_prefix
A default router list with entries of type uip_nd6_defrouter

Each of this structure has its own add, remove and lookup functions. To update an entry in a ND structure, we first do a lookup to obtain a pointer to the entry, we then directly modify the different entry fields.

Neighbor discovery processes

Address resolution
Determine the link-layer address of a neighbor given its IPv6 address.
-> send a NS (done in tcpip_ipv6_output).
Neighbor unreachability detection
Verify that a neighbor is still reachable via a cached link-layer address.
-> send a NS (done in uip_nd6_periodic).
Next-hop determination
Map an IPv6 destination address into the IPv6 address of the neighbor to which traffic for the destination should be sent.
-> look at on-link prefixes, if the destination is not on-link, choose a default router, else send directly (done in tcpip_ipv6_output).
Router, prefix, and parameter discovery
Update the list of default routers, on-link prefixes, and the network parameters.
-> receive a RA (see uip_nd6_io_ra_input).

Stateless Address Autoconfiguration (RFC 4862)

RFC 4862 defines two main processes:

Duplicate Address Detection (DAD)
Make sure that an address the node wished to use is not already in use by another node.
-> send a NS (done in uip_netif_dad)
Address Autoconfiguration
Configure an address for an interface by combining a received prefix and the interface ID (see uip_netif_addr_add). The interface ID is obtained from the link-layer address using uip_netif_get_interface_id.
-> Receive a RA with a prefix information option that has the autonomous flag set.

When an interface becomes active, its link-local address is created by combining the FE80::0/64 prefix and the interface ID. DAD is then performed for this link-local address. Available routers are discovered by sending up to UIP_ND6_MAX_RTR_SOLICITATIONS RS packets. Address autoconfiguration is then performed based on the prefix information received in the RA. The interface initialization is performed in uip_netif_init.

ICMPv6 (RFC 4443)

We support ICMPv6 Error messages as well as Echo Reply and Echo Request messages. The application used for sending Echo Requests (see ping6.c) is not part of the IP stack.

Note:: RFC 4443 stipulates that 'Every ICMPv6 error message MUST include as much of the IPv6 offending (invoking) packet as possible'. In a constrained environment this is not very resource friendly.

The ICMPv6 message headers and constants are defined in uip-icmp6.h.

IPv6 Timers and Processes

The IPv6 stack (like the IPv4 stack) is a Contiki process

PROCESS(tcpip_process, "TCP/IP stack");

In addition to the periodic timer that is used by TCP, five IPv6 specific timers are attached to this process:

The uip_nd6_timer_periodic is used for periodic checking of the neighbor discovery structures.
The uip_netif_timer_dad is used to properly paced the Neighbor Solicitation packets sent for Duplicate Address Detection.
The uip_netif_timer_rs is use to delay the sending of Router Solicitations packets in particular during the router discovery process.
The uip_netif_timer_periodic is used to periodically check the validity of the addresses attached to the network interface.
The uip_reass_timer is used to time-out the fragment reassembly process.

Both uip_nd6_timer_periodic and uip_netif_timer_periodic run continuously. This could be avoided by using callback timers to handle ND and Netif structures timeouts.

Compile time flags and variables

This section just lists all IPv6 related compile time flags. Each flag function is documented in this page in the appropriate section.

/*Boolean flags*/
UIP_CONF_IPV6        
UIP_CONF_IPV6_CHECKS
UIP_CONF_IPV6_QUEUE_PKT 
UIP_CONF_IPV6_REASSEMBLY        
/*Integer flags*/
UIP_NETIF_MAX_ADDRESSES 
UIP_ND6_MAX_PREFIXES   
UIP_ND6_MAX_NEIGHBORS   
UIP_ND6_MAX_DEFROUTER

IPv6 Buffers

The IPv6 code uses the same single global buffer as the IPv4 code. This buffer should be large enough to contain one packet of maximum size, i.e., UIP_LINK_MTU = 1280 bytes. When fragment reassembly is enabled an additional buffer of the same size is used.

The only difference with the IPv4 code is the per neighbor buffering that is available when UIP_CONF_QUEUE_PKT is set to 1. This additional buffering is used to queue one packet per neighbor while performing address resolution for it. This is a very costly feature as it increases the RAM usage by approximately UIP_ND6_MAX_NEIGHBORS * UIP_LINK_MTU bytes.

IPv6 Code Size

Note:

We used Atmel's RAVEN boards with the Atmega1284P MCU (128Kbyte of flash and 16Kbyte of SRAM) to benchmark our code. These numbers are obtained using 'avr-gcc 4.2.2 (WinAVR 20071221)'. Elf is the output format.

The following compilation flags were used:

UIP_CONF_IPV6            1      
UIP_CONF_IPV6_CHECKS     1      
UIP_CONF_IPV6_QUEUE_PKT  0      
UIP_CONF_IPV6_REASSEMBLY 0      

UIP_NETIF_MAX_ADDRESSES 3
UIP_ND6_MAX_PREFIXES    3
UIP_ND6_MAX_NEIGHBORS   4
UIP_ND6_MAX_DEFROUTER   2

The total IPv6 code size is approximately 11.5Kbyte and the RAM usage around 1.8Kbyte. For an additional NEIGHBOR count 35bytes, 25 for an additional PREFIX, 7 for an additional DEFROUTER, and 25 for an additional ADDRESS.

IPv6 Link Layer dependencies

The IPv6 stack can potentially run on very different link layers (ethernet, 802.15.4, 802.11, etc). The link-layer influences the following IP layer objects:

uip_lladdr_t, the link-layer address type, and its length, UIP_LLADDR_LEN.

struct uip_eth_addr {
  u8_t addr[6];
};
typedef struct uip_eth_addr uip_lladdr_t;
#define UIP_LLADDR_LEN 6

uip_lladdr, the link-layer address of the node.

uip_lladdr_t uip_lladdr = {{0x00,0x06,0x98,0x00,0x02,0x32}};

UIP_ND6_OPT_LLAO_LEN, the length of the link-layer option in the different ND messages

Moreover, tcpip_output should point to the link-layer function used to send a packet. Similarly, the link-layer should call tcpip_input when an IP packet is received.

The code corresponding to the desired link layer is selected at compilation time (see for example the UIP_LL_802154 flag).

IPv6 interaction with upper layers

The TCP and the UDP protocol are part of the uIP stack and were left unchanged by the IPv6 implementation. For the application layer, please refer to the application program interface.

IPv6 compliance

IPv6 Node Requirements, RFC4294

This section describes which parts of RFC4294 we are compliant with. For each section, we put between brackets the requirement level.
When all IPv6 related compile flags are set, our stack is fully compliant with RFC4294 (i.e. we implemement all the MUSTs), except for MLD support and redirect function support.

Note:: RFC4294 is currently being updated by IETF 6man WG. One of the important points for us in the update is that after discussion on the 6man mailing list, IPSec support will become a SHOULD (was a MUST).

Sub IP layer
We support RFC2464 transmission of IPv6 packets over Ethernet
We will soon support RFC4944 transmission of IPv6 packets over 802.15.4

IP layer

IPv6 RFC2460 (MUST): When the compile flags UIP_CONF_IPV6_CHECKS and UIP_CONF_REASSEMBLY are set, full support
Neighbor Discovery RFC4861 (MUST): When the UIP_CONF_CHECKS and UIP_CONF_QUEUE_PKT flag are set, full support except redirect function
Address Autoconfiguration RFC4862 (MUST): When the UIP_CONF_CHECKS flag is set, full support except sending MLD report (see MLD)
Path MTU Discovery RFC 1981 (SHOULD): no support
Jumbograms RFC 2675 (MAY): no support
ICMPv6 RFC 4443 (MUST): full support
IPv6 addressing architecture RFC 3513 (MUST): full support
Privacy extensions for address autoconfiguration RFC 3041 (SHOULD): no support.
Default Address Selection RFC 3484 (MUST): full support.
MLDv1 (RFC 2710) and MLDv2 (RFC 3810) (conditional MUST applying here): no support. As we run IPv6 over Multicast or broadcast capable links (Ethernet or 802.15.4), the conditional MUST applies. We should be able to send an MLD report when joining a solicited node multicast group at address configuration time. This will be available in a later release.

DNS (RFC 1034, 1035, 3152, 3363, 3596) and DHCPv6 (RFC 3315) (conditional MUST)
no support

IPv4 Transition mechanisms RFC 4213 (conditional MUST)
no support

Mobile IP RFC 3775 (MAY / SHOULD)
no support

IPSec RFC 4301 4302 4303 2410 2404 2451 3602(MUSTs) 4305 (SHOULD)
no support

SNMP (MAY)
no support

IPv6 certification through ipv6ready alliance

IPv6ready is the certification authority for IPv6 implementations (http://www.ipv6ready.org). It delivers two certificates (phase 1 and phase 2).
When all the IPv6 related compile flags are set, we pass all the tests for phase 1.
We pass all the tests for phase 2 except:

the tests related to the redirect function
the tests related to PMTU discovery
test v6LC1.3.2C: A "bug" in the test suite (fragmentation states are not deleted after test v6LC1.3.2B) makes us fail this test unless we run it individually.
5.1.3: UDP port unreachable (the UDP message is too large for our implementation and the UDP code does not send any ICMP error message)

Define Documentation

#define uip_ds6_is_my_addr ( addr ) (uip_ds6_addr_lookup(addr) != NULL)

Definition at line 415 of file uip-ds6.h.

Referenced by uip_nd6_ns_input(), uip_nd6_ns_output(), and uip_process().

#define UIP_DS6_NBR_NBS 0

Configuration.

For all tables (Neighbor cache, Prefix List, Routing Table, Default Router List, Unicast address list, multicast address list, anycast address list), we define:

the number of elements requested by the user in contiki configuration (name suffixed by _NBU)
the number of elements assigned by the system (name suffixed by _NBS)
the total number of elements is the sum (name suffixed by _NB)

Definition at line 57 of file uip-ds6.h.

#define UIP_ND6_MAX_RTR_SOLICITATION_DELAY 1

Definition at line 81 of file uip-nd6.h.

#define UIP_ND6_NA_FLAG_ROUTER 0x80

Definition at line 179 of file uip-nd6.h.

Referenced by uip_nd6_na_input().

#define UIP_ND6_NA_LEN 20

Definition at line 143 of file uip-nd6.h.

Referenced by uip_nd6_na_input(), and uip_nd6_ns_input().

#define UIP_ND6_OPT_HDR_LEN 2

Definition at line 152 of file uip-nd6.h.

#define UIP_ND6_OPT_LLAO_LEN 8

length of a ND6 LLAO option for default L2 type (e.g.

Ethernet)

Definition at line 171 of file uip-nd6.h.

Referenced by uip_nd6_ns_input(), uip_nd6_ns_output(), and uip_nd6_rs_output().

#define UIP_ND6_OPT_SLLAO 1

Definition at line 128 of file uip-nd6.h.

Referenced by mac_translateIcmpLinkLayer(), uip_nd6_ns_input(), uip_nd6_ns_output(), uip_nd6_ra_input(), and uip_nd6_rs_output().

#define UIP_ND6_OPT_TYPE_OFFSET 0

Definition at line 137 of file uip-nd6.h.

#define UIP_ND6_RS_BUF ((uip_nd6_rs *)&uip_buf[uip_l2_l3_icmp_hdr_len])

Pointers to messages just after icmp header

Definition at line 115 of file uip-nd6.c.

#define UIP_ND6_SEND_RA 1

Definition at line 89 of file uip-nd6.h.

Typedef Documentation

typedef struct uip_ds6_addr uip_ds6_addr_t

*

Unicast address structure

Enumeration Type Documentation

enum uip_neighbor_state

Possible states for the neighbor cache entries.

NO_STATE is for implementation purposes: a router entry contains a pointer to a neighbor entry, which holds its ip address. If we do not know the LL address of the router, we do not have to create a neighbor entry as per RFC 4861. However, we still need to have the IP of the router stored in a neighbor entry, hence we create an entry in the NO_STATE state

Definition at line 196 of file uip-nd6.h.

Function Documentation

u16_t uip_chksum	(	u16_t *	buf,
		u16_t	len
	)

Calculate the Internet checksum over a buffer.

The Internet checksum is the one's complement of the one's complement sum of all 16-bit words in the buffer.

See RFC1071.

Note:: This function is not called in the current version of uIP, but future versions might make use of it.

Parameters:

	buf	A pointer to the buffer over which the checksum is to be computed.
	len	The length of the buffer over which the checksum is to be computed.

Returns:: The Internet checksum of the buffer.

The Internet checksum is the one's complement of the one's complement sum of all 16-bit words in the buffer.

See RFC1071.

Parameters:

	buf	A pointer to the buffer over which the checksum is to be computed.
	len	The length of the buffer over which the checksum is to be computed.

Returns:: The Internet checksum of the buffer.

Definition at line 339 of file uip6.c.

uip_ds6_aaddr_t * uip_ds6_aaddr_add ( uip_ipaddr_t * ipaddr )

uip_ds6_addr_t * uip_ds6_addr_add	(	uip_ipaddr_t *	ipaddr,
		unsigned long	vlifetime,
		uint8_t	type
	)

Referenced by main(), and uip_nd6_ra_input().

uip_ds6_defrt_t * uip_ds6_defrt_add	(	uip_ipaddr_t *	ipaddr,
		unsigned long	interval
	)

Referenced by uip_nd6_ra_input().

uip_ds6_maddr_t * uip_ds6_maddr_add ( uip_ipaddr_t * ipaddr )

uip_ds6_nbr_t * uip_ds6_nbr_add	(	uip_ipaddr_t *	ipaddr,
		uip_lladdr_t *	lladdr,
		uint8_t	isrouter,
		uint8_t	state
	)

Referenced by uip_nd6_ns_input(), and uip_nd6_ra_input().

uip_ds6_prefix_t * uip_ds6_prefix_add	(	uip_ipaddr_t *	ipaddr,
		uint8_t	length,
		unsigned long	interval
	)

Referenced by main(), and uip_nd6_ra_input().

uip_ds6_route_t * uip_ds6_route_lookup ( uip_ipaddr_t * destipaddr )

u16_t uip_htons ( u16_t val )

Convert 16-bit quantity from host byte order to network byte order.

This function is primarily used for converting variables from host byte order to network byte order. For converting constants to network byte order, use the UIP_HTONS() macro instead.

Definition at line 2193 of file uip6.c.

References UIP_HTONS.

void uip_icmp6_echo_request_input ( void )

\ brief Process an echo request

Perform a few checks, then send an Echo reply. The reply is built here.

Referenced by uip_process().

void uip_icmp6_error_output	(	u8_t	type,
		u8_t	code,
		u32_t	param
	)

Send an icmpv6 error message.

Parameters:

	type	type of the error message
	code	of the error message
	type	32 bit parameter of the error message, semantic depends on error

Referenced by uip_process().

void uip_icmp6_send	(	uip_ipaddr_t *	dest,
		int	type,
		int	code,
		int	payload_len
	)

Send an icmpv6 message.

Parameters:

	dest	destination address of the message
	type	type of the message
	code	of the message
	payload_len	length of the payload

u16_t uip_icmp6chksum ( void )

Calculate the ICMP checksum of the packet in uip_buf.

Returns:: The ICMP checksum of the ICMP packet in uip_buf

Definition at line 378 of file uip6.c.

Referenced by mac_translateIcmpLinkLayer(), uip_nd6_ns_input(), uip_nd6_ns_output(), uip_nd6_rs_output(), and uip_process().

void uip_init ( void )

uIP initialization function.

This function should be called at boot up to initilize the uIP TCP/IP stack.

Definition at line 402 of file uip6.c.

References uip_udp_conn::lport, uip_conn::tcpstateflags, UIP_CONNS, uip_ds6_init(), UIP_LISTENPORTS, and UIP_UDP_CONNS.

u16_t uip_ipchksum ( void )

Calculate the IP header checksum of the packet header in uip_buf.

The IP header checksum is the Internet checksum of the 20 bytes of the IP header.

Returns:: The IP header checksum of the IP header in the uip_buf buffer.

Definition at line 346 of file uip6.c.

struct uip_nd6_defrouter* uip_nd6_defrouter_add	(	struct uip_nd6_neighbor *	neighbor,
		unsigned long	interval
	)			`[read]`

Add a default router.

Parameters:

	neighbor	the corresponding neighbor cache entry
	interval	the lifetime of the router

Returns:: the new or updated defrouter entry

struct uip_nd6_defrouter* uip_nd6_defrouter_lookup ( struct uip_nd6_neighbor * neighbor ) [read]

Find a default router corresponding to a given neighbor cache entry.

Parameters:

neighbor

the neighbor cache entry

Returns:: the corresponding router if any

void uip_nd6_defrouter_rm ( struct uip_nd6_defrouter * router )

Remove a default router.

Parameters:

router

to be removed

u8_t uip_nd6_is_addr_onlink ( uip_ipaddr_t * ipaddr )

Check if an IP address in on-link by looking at prefix list.

Parameters:

ipaddr

an IP address

Returns:: true if on-link

void uip_nd6_na_input ( void )

Process a Neighbor Advertisement.

we might have to send a pkt that had been buffered while address resolution was performed (if we support buffering, see UIP_CONF_QUEUE_PKT)

As per RFC 4861, on link layer that have addresses, TLLAO options MUST be included when responding to multicast solicitations, SHOULD be included in response to unicast (here we assume it is for now)

NA can be received after sending NS for DAD, Address resolution or NUD. Can be unsolicited as well. It can trigger update of the state of the neighbor in the neighbor cache, router in the router list. If the NS was for DAD, it means DAD failed

Definition at line 389 of file uip-nd6.c.

References ADDR_TENTATIVE, NBR_INCOMPLETE, stimer_set(), uip_ds6_dad_failed(), uip_ds6_if, UIP_ICMP_BUF, UIP_IP_BUF, uip_len, UIP_ND6_HOP_LIMIT, UIP_ND6_NA_FLAG_ROUTER, UIP_ND6_NA_LEN, UIP_ND6_OPT_HDR_BUF, and UIP_STAT.

Referenced by uip_process().

struct uip_nd6_neighbor* uip_nd6_nbrcache_add	(	uip_ipaddr_t *	ipaddr,
		uip_lladdr_t *	lladdr,
		u8_t	isrouter,
		uip_neighbor_state	state
	)			`[read]`

Add a neighbor cache entry.

Parameters:

	ipaddr	the IP address of the entry
	lladdr	the layer 2 address of the entry
	isrouter	true is the entry is a router
	state	the state of the entry

Returns:: the new neighbor or updated cache entry

struct uip_nd6_neighbor* uip_nd6_nbrcache_lookup ( uip_ipaddr_t * ipaddr ) [read]

Look for a neighbor cache entry corresponding to a specific IP address.

Parameters:

ipaddr

the specific IP address

Returns:: the corresponding neighbor cache entry

void uip_nd6_ns_input ( void )

Process a neighbor solicitation.

The NS can be received in 3 cases (procedures):

sender is performing DAD (ip src = unspecified, no SLLAO option)
sender is performing NUD (ip dst = unicast)
sender is performing address resolution (ip dest = solicited node mcast address)

We do:

if the tgt belongs to me, reply, otherwise ignore
if i was performing DAD for the same address, two cases: -- I already sent a NS, hence I win -- I did not send a NS yet, hence I lose

If we need to send a NA in response (i.e. the NS was done for NUD, or address resolution, or DAD and there is a conflict), we do it in this function: set src, dst, tgt address in the three cases, then for all cases set the rest, including SLLAO

Todo:: if I sent a NS before him, I win

Definition at line 155 of file uip-nd6.c.

References ADDR_TENTATIVE, ICMP6_NA, NBR_INCOMPLETE, uip_ds6_dad_failed(), uip_ds6_is_my_addr, uip_ds6_nbr_add(), uip_ds6_select_src(), uip_ext_len, uip_icmp6chksum(), UIP_ICMP_BUF, UIP_IP_BUF, uip_ipaddr_copy, uip_len, UIP_ND6_HOP_LIMIT, UIP_ND6_NA_LEN, UIP_ND6_OPT_HDR_BUF, UIP_ND6_OPT_LLAO_LEN, UIP_ND6_OPT_SLLAO, and UIP_STAT.

Referenced by uip_process().

void uip_nd6_ns_output	(	uip_ipaddr_t *	src,
		uip_ipaddr_t *	dest,
		uip_ipaddr_t *	tgt
	)

Send a neighbor solicitation, send a Neighbor Advertisement.

Parameters:

	src	pointer to the src of the NS if known
	dest	pointer to ip address to send the NS, for DAD or ADDR Resol, MUST be NULL, for NUD, must be correct unicast dest
	tgt	pointer to ip address to fill the target address field, must not be NULL

RFC 4861, 7.2.2 : If the source address of the packet prompting the solicitation is the same as one of the addresses assigned to the outgoing interface, that address SHOULD be placed in the IP Source Address of the outgoing solicitation. Otherwise, any one of the addresses assigned to the interface should be used. This is why we have a src ip address as argument. If NULL, we will do src address selection, otherwise we use the argument.

we check if it is a NS for Address resolution or NUD, if yes we include a SLLAO option, otherwise no.

Definition at line 328 of file uip-nd6.c.

References ICMP6_NS, uip_ds6_is_my_addr, uip_ds6_select_src(), uip_ext_len, uip_icmp6chksum(), UIP_ICMP_BUF, UIP_IP_BUF, uip_ipaddr_copy, uip_len, UIP_ND6_HOP_LIMIT, UIP_ND6_OPT_LLAO_LEN, UIP_ND6_OPT_SLLAO, and UIP_STAT.

struct uip_nd6_prefix* uip_nd6_prefix_add	(	uip_ipaddr_t *	ipaddr,
		u8_t	length,
		unsigned long	interval
	)			`[read]`

Add a prefix.

Parameters:

	ipaddr	the IP address of the prefix
	length	the length of the prefix
	interval	the lifetime of the prefix

Returns:: the new or updated prefix entry

struct uip_nd6_prefix* uip_nd6_prefix_lookup ( uip_ipaddr_t * ipaddr ) [read]

Find a given prefix.

Parameters:

ipaddr

an IP address

Returns:: the corresponding prefix if any

void uip_nd6_prefix_rm ( struct uip_nd6_prefix * prefix )

Remove a prefix from th eprefix list.

Parameters:

prefix

pointer to the prefix to be removed

void uip_nd6_ra_input ( void )

process a Router Advertisement

Possible actions when receiving a RA: add router to router list, recalculate reachable time, update link hop limit, update retrans timer.
If MTU option: update MTU.
If SLLAO option: update entry in neighbor cache
If prefix option: start autoconf, add prefix to prefix list

Definition at line 746 of file uip-nd6.c.

References NBR_INCOMPLETE, stimer_remaining(), stimer_set(), uip_ds6_addr_add(), uip_ds6_compute_reachable_time(), uip_ds6_defrt_add(), uip_ds6_if, uip_ds6_nbr_add(), uip_ds6_prefix_add(), uip_ds6_set_addr_iid(), UIP_ICMP_BUF, UIP_IP_BUF, uip_ipaddr_copy, uip_len, uip_lladdr, UIP_ND6_HOP_LIMIT, UIP_ND6_INFINITE_LIFETIME, UIP_ND6_OPT_HDR_BUF, UIP_ND6_OPT_SLLAO, and UIP_STAT.

Referenced by uip_process().

void uip_nd6_rs_output ( void )

Send a Router Solicitation.

src is chosen through the uip_netif_select_src function. If src is unspecified (i.e. we do not have a preferred address yet), then we do not put a SLLAO option (MUST NOT in RFC 4861). Otherwise we do.

RS message format, possible option is SLLAO, MUST NOT be included if source = unspecified SHOULD be included otherwise

Definition at line 706 of file uip-nd6.c.

References ICMP6_RS, uip_ds6_select_src(), uip_icmp6chksum(), UIP_ICMP_BUF, UIP_IP_BUF, uip_len, UIP_ND6_HOP_LIMIT, UIP_ND6_OPT_LLAO_LEN, UIP_ND6_OPT_SLLAO, and UIP_STAT.

void uip_process ( u8_t flag )

Note:: We don't implement any application callback for now

Definition at line 866 of file uip6.c.

References ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, ICMP6_DST_UNREACH_NOTNEIGHBOR, ICMP6_ECHO_REPLY, ICMP6_ECHO_REQUEST, ICMP6_NA, ICMP6_NS, ICMP6_PACKET_TOO_BIG, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, ICMP6_PARAMPROB_NEXTHEADER, ICMP6_RA, ICMP6_RPL, ICMP6_RS, ICMP6_TIME_EXCEED_TRANSIT, ICMP6_TIME_EXCEEDED, uip_conn::initialmss, uip_conn::len, uip_conn::lport, uip_udp_conn::lport, uip_conn::mss, uip_conn::nrtx, uip_conn::rcv_nxt, uip_conn::ripaddr, uip_udp_conn::ripaddr, uip_conn::rport, uip_udp_conn::rport, uip_conn::rto, uip_conn::sa, uip_conn::snd_nxt, uip_conn::sv, uip_conn::tcpstateflags, uip_conn::timer, uip_udp_conn::ttl, uip_add32(), UIP_APPCALL, uip_appdata, uip_ds6_if, uip_ds6_is_my_addr, uip_ds6_select_src(), uip_ext_bitmap, uip_ext_len, UIP_HTONS, uip_icmp6_echo_request_input(), uip_icmp6_error_output(), uip_icmp6chksum(), UIP_ICMP_BUF, UIP_IP_BUF, uip_ipaddr_cmp, uip_ipaddr_copy, uip_len, UIP_LINK_MTU, UIP_LLH_LEN, UIP_MAXRTX, UIP_MAXSYNRTX, uip_nd6_na_input(), uip_nd6_ns_input(), uip_nd6_ra_input(), uip_next_hdr, UIP_RECEIVE_WINDOW, UIP_RTO, UIP_STAT, UIP_TCP_MSS, uip_tcpchksum(), UIP_TIME_WAIT_TIMEOUT, UIP_UDP_CONNS, and uip_udpchksum().

void uip_send	(	const void *	data,
		int	len
	)

Send data on the current connection.

This function is used to send out a single segment of TCP data. Only applications that have been invoked by uIP for event processing can send data.

The amount of data that actually is sent out after a call to this function is determined by the maximum amount of data TCP allows. uIP will automatically crop the data so that only the appropriate amount of data is sent. The function uip_mss() can be used to query uIP for the amount of data that actually will be sent.

Note:: This function does not guarantee that the sent data will arrive at the destination. If the data is lost in the network, the application will be invoked with the uip_rexmit() event being set. The application will then have to resend the data using this function.

Parameters:

	data	A pointer to the data which is to be sent.
	len	The maximum amount of data bytes to be sent.

Definition at line 2205 of file uip6.c.

References UIP_BUFSIZE, and UIP_LLH_LEN.

struct uip_udp_conn* uip_udp_new	(	const uip_ipaddr_t *	ripaddr,
		u16_t	rport
	)			`[read]`

Set up a new UDP connection.

This function sets up a new UDP connection. The function will automatically allocate an unused local port for the new connection. However, another port can be chosen by using the uip_udp_bind() call, after the uip_udp_new() function has been called.

Example:

 uip_ipaddr_t addr;
 struct uip_udp_conn *c;
 
 uip_ipaddr(&addr, 192,168,2,1);
 c = uip_udp_new(&addr, UIP_HTONS(12345));
 if(c != NULL) {
 uip_udp_bind(c, UIP_HTONS(12344));
 }

Parameters:

	ripaddr	The IP address of the remote host.
	rport	The remote port number in network byte order.

Returns:: The uip_udp_conn structure for the new connection or NULL if no connection could be allocated.

Definition at line 498 of file uip6.c.

References uip_udp_conn::lport, uip_udp_conn::ripaddr, uip_udp_conn::rport, uip_udp_conn::ttl, uip_ds6_if, UIP_HTONS, uip_htons(), uip_ipaddr_copy, UIP_TTL, and UIP_UDP_CONNS.

Variable Documentation

void* uip_appdata

Pointer to the application data in the packet buffer.

This pointer points to the application data when the application is called. If the application wishes to send data, the application may use this space to write the data into before calling uip_send().

Definition at line 177 of file uip6.c.

struct uip_conn* uip_conn

Pointer to the current TCP connection.

The uip_conn pointer can be used to access the current TCP connection.

Definition at line 200 of file uip6.c.

uip_ds6_netif_t uip_ds6_if

Definition at line 75 of file uip-ds6.c.

uip_ds6_netif_t uip_ds6_if

Definition at line 75 of file uip-ds6.c.

Referenced by main(), menu_process(), uip_nd6_na_input(), uip_nd6_ra_input(), uip_process(), and uip_udp_new().

u8_t uip_ext_len = 0

length of the extension headers read.

The length of the extension headers.

updated each time we process a header

Definition at line 143 of file uip6.c.

Referenced by tcpip_input(), uip_nd6_ns_input(), uip_nd6_ns_output(), and uip_process().

u16_t uip_len

The length of the packet in the uip_buf buffer.

The global variable uip_len holds the length of the packet in the uip_buf buffer.

When the network device driver calls the uIP input function, uip_len should be set to the length of the packet in the uip_buf buffer.

When sending packets, the device driver should use the contents of the uip_len variable to determine the length of the outgoing packet.

Definition at line 188 of file uip6.c.

u8_t* uip_next_hdr

Type of the next header in IPv6 header or extension headers.

Can be the next header field in the IPv6 header or in an extension header. When doing fragment reassembly, we must change the value of the next header field in the header before the fragmentation header, hence we need a pointer to this field.

Definition at line 136 of file uip6.c.

Referenced by uip_process().

uIP IPv6 specific features [The uIP TCP/IP stack]

Data Structures

Files

Defines

Typedefs

Enumerations

Functions

Variables

"DS6" Data structures

Layer 2 variables

Layer 3 variables

Buffer variables

General variables

UDP variables

Neighbor Cache basic routines

Default router list basic routines

Prefix list basic routines

Unicast address list basic routines

Multicast address list basic routines

Anycast address list basic routines

Routing Table basic routines

ICMPv6 RFC4443 Message processing and sending

ND Neighbor Cache, Router List and Prefix List handling functions

ND Messages Processing and Generation

Macros to check if an IP address (unicast, multicast or anycast) is mine

ICMPv6 message types

ICMPv6 Destination Unreachable message codes

ICMPv6 Time Exceeded message codes

ICMPv6 Parameter Problem message codes

Pointers to the header structures.

General

Configuration options

RFC 4861 Host constant

RFC 4861 Router constants

RFC 4861 Node constant

ND6 option types

ND6 message length (excluding options)

ND6 option length in bytes

Neighbor Advertisement flags masks

Buffer defines

TCP defines

Detailed Description

Define Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation

Variable Documentation

uIP IPv6 specific features
[The uIP TCP/IP stack]