Sicslowpan

Data Structures
struct	sicslowpan_addr_context
	An address context for IPHC address compression each context can have upto 8 bytes. More...
struct	sicslowpan_nh_compressor
	The structure of a next header compressor. More...

Macros
#define	LOG_MODULE   "6LoWPAN"
	FOR RFC 6282 COMPLIANCE TODO: -Add compression options to UDP, currently only supports both ports compressed or both ports elided.

Functions
static void	digest_paging_dispatch (void)
	Digest 6lorh headers before IPHC.
static void	digest_6lorh_hdr (void)
	Digest 6lorh headers before IPHC.

General variables
static uint8_t *	packetbuf_ptr
	A pointer to the packetbuf buffer.
static uint8_t	packetbuf_hdr_len
	packetbuf_hdr_len is the total length of (the processed) 6lowpan headers (fragment headers, IPV6 or HC1, HC2, and HC1 and HC2 non compressed fields).
static int	packetbuf_payload_len
	The length of the payload in the Packetbuf buffer.
static uint8_t	uncomp_hdr_len
	uncomp_hdr_len is the length of the headers before compression (if HC2 is used this includes the UDP header in addition to the IP header).
static int	mac_max_payload
	mac_max_payload is the maimum payload space on the MAC frame.
static uint8_t	curr_page
	The current page (RFC 4944).
static int	last_tx_status
	the result of the last transmitted fragment

Input/output functions common to all compression schemes
static void	packet_sent (void *ptr, int status, int transmissions)
	Callback function for the MAC packet sent callback.
static void	send_packet (void)
	This function is called by the 6lowpan code to send out a packet.
static uint8_t	output (const linkaddr_t *localdest)
	Take an IP packet and format it to be sent on an 802.15.4 network using 6lowpan.
static void	input (void)
	Process a received 6lowpan packet.

Address compressibility test functions
#define	sicslowpan_is_iid_16_bit_compressable(a)
	check whether we can compress the IID in address 'a' to 16 bits.
#define	sicslowpan_is_mcast_addr_decompressable(a)
	check whether the 9-bit group-id of the compressed multicast address is known.
#define	sicslowpan_is_mcast_addr_compressable(a)
	check whether the 112-bit group-id of the multicast address is mappable to a 9-bit group-id It is true if the group is the all nodes or all routers group.

Detailed Description

Macro Definition Documentation

LOG_MODULE

#define LOG_MODULE   "6LoWPAN"

FOR RFC 6282 COMPLIANCE TODO: -Add compression options to UDP, currently only supports both ports compressed or both ports elided.

-Verify TC/FL compression works

-Add stateless multicast option

Definition at line 82 of file sicslowpan.c.

sicslowpan_is_iid_16_bit_compressable

#define sicslowpan_is_iid_16_bit_compressable

(

a

)

Value:

((((a)->u16[4]) == 0) &&                       \
 (((a)->u8[10]) == 0)&&                           \
 (((a)->u8[11]) == 0xff)&&                        \
 (((a)->u8[12]) == 0xfe)&&                        \
 (((a)->u8[13]) == 0))

check whether we can compress the IID in address 'a' to 16 bits.

This is used for unicast addresses only, and is true if the address is on the format <PREFIX>::0000:00ff:fe00:XXXX NOTE: we currently assume 64-bits prefixes

Definition at line 213 of file sicslowpan.h.

sicslowpan_is_mcast_addr_decompressable

#define sicslowpan_is_mcast_addr_decompressable

(

a

)

Value:

(((*a & 0x01) == 0) &&                           \
 ((*(a + 1) == 0x01) || (*(a + 1) == 0x02)))

check whether the 9-bit group-id of the compressed multicast address is known.

It is true if the 9-bit group is the all nodes or all routers group.

Parameters

a	is typed uint8_t *

Definition at line 227 of file sicslowpan.h.

Function Documentation

input()

void input ( void )

static

Process a received 6lowpan packet.

The 6lowpan packet is put in packetbuf by the MAC. If its a frag1 or a non-fragmented packet we first uncompress the IP header. The 6lowpan payload and possibly the uncompressed IP header are then copied in siclowpan_buf. If the IP packet is complete it is copied to uip_buf and the IP layer is called.

Note

We do not check for overlapping sicslowpan fragments (it is a SHALL in the RFC 4944 and should never happen)

Definition at line 1850 of file sicslowpan.c.

References curr_page, digest_6lorh_hdr(), digest_paging_dispatch(), packetbuf_datalen(), packetbuf_dataptr(), packetbuf_hdr_len, packetbuf_payload_len, packetbuf_ptr, SICSLOWPAN_COMPRESSION, tcpip_input(), uip_buf, UIP_BUFSIZE, UIP_IP_BUF, uip_len, and uncomp_hdr_len.

output()

uint8_t output ( const linkaddr_t * localdest )

static

Take an IP packet and format it to be sent on an 802.15.4 network using 6lowpan.

Parameters

localdest

The MAC address of the destination

The IP packet is initially in uip_buf. Its header is compressed and if necessary it is fragmented. The resulting packet/fragments are put in packetbuf and delivered to the 802.15.4 MAC.

Definition at line 1623 of file sicslowpan.c.

References last_tx_status, linkaddr_null, mac_max_payload, MAC_TX_OK, packetbuf_clear(), packetbuf_dataptr(), packetbuf_hdr_len, packetbuf_payload_len, packetbuf_ptr, packetbuf_set_datalen(), send_packet(), UIP_IP_BUF, uip_is_addr_linklocal, uip_len, and uncomp_hdr_len.

Variable Documentation

packetbuf_payload_len

int packetbuf_payload_len

static

The length of the payload in the Packetbuf buffer.

The payload is what comes after the compressed or uncompressed headers (can be the IP payload if the IP header only is compressed or the UDP payload if the UDP header is also compressed)

Definition at line 175 of file sicslowpan.c.

Referenced by input(), and output().

packetbuf_ptr

uint8_t* packetbuf_ptr

static

A pointer to the packetbuf buffer.

We initialize it to the beginning of the packetbuf buffer, then access different fields by updating the offset packetbuf_hdr_len.

Definition at line 160 of file sicslowpan.c.

Referenced by input(), and output().