spinn_net.c File Reference

Ethernet/IP support routines for Spinnaker. More...

#include "spinnaker.h"
#include "sark.h"
#include "scamp.h"
#include "spinn_net.h"
#include <string.h>

Data Structures
struct	arp_entry
	An ARP cache entry. More...

Macros
#define	MAX_ARP_ENTRIES   5
	Max size of ARP cache.

Functions
static void	eth_discard (void)
	Clear the ethernet receive buffer.
void	eth_init (uchar *mac)
	Initialise the ethernet subsystem.
uint	ipsum (uchar *d, uint len, uint sum)
	Compute an IP checksum.
void	copy_mac (const uchar *f, uchar *t)
	Copy MAC address.
void	copy_ip (const uchar *f, uchar *t)
	Copy IP address.
uint	cmp_ip (const uchar *a, const uchar *b)
	Compare IP addresses.
void	copy_ip_hdr (uchar *dest, uint prot, ip_hdr_t *ip, uint len)
	Initialise IP header.
void	eth_transmit (uchar *buf, uint len, uint type, const uchar *dest)
	Transmit ethernet packet.
void	eth_transmit2 (uchar *hdr, uchar *buf, uint hdr_len, uint buf_len)
	Transmit ethernet packet.
void	send_arp_pkt (uchar *buf, const uchar *dest, const uchar *tha, const uchar *tpa, uint type)
	Send an ARP packet.
void	arp_lookup (iptag_t *iptag)
	Initiate ARP lookup if required. Lookup might be immediate (out of cache) or require network traffic.
void	arp_pkt (uchar *rx_pkt, uint rx_len, uint tag_table_size)
	ARP packet received handler.
void	arp_add (uchar *mac, uchar *ip)
	Add a MAC/IP address binding to our ARP cache.
void	icmp_pkt (uchar *rx_pkt, uint rx_len)
	ICMP packet received handler.
void	copy_udp (uchar *buf, uint len, uint dest, uint srce)
	Initialise UDP packet header.

Variables
srom_data_t	srom
	Copy of SROM struct.
iptag_t	tag_table []
	Table of all IPTags.
const uchar	bc_mac [] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
	Broadcast MAC address.
const uchar	zero_mac [] = {0, 0, 0, 0, 0, 0}
	Zero MAC address.
static struct arp_entry	arp_entries [MAX_ARP_ENTRIES]
	The ARP cache.
static uint	next_arp_entry = MAX_ARP_ENTRIES
	Which is the next ARP cache entry to allocate (or evict and reuse)

Detailed Description

Ethernet/IP support routines for Spinnaker.

Copyright

© The University of Manchester - 2009, 2010

Author

Steve Temple, APT Group, School of Computer Science

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Data Structure Documentation

arp_entry

struct arp_entry

An ARP cache entry.

This remembers what MAC address to send an ethernet packet to in order to deliver an IP packet to a particular address. That MAC address might be the address of a router, not the target machine.

Data Fields
uchar	mac[6]	The MAC address.
uchar	ip[4]	The IP address.
struct arp_entry *	next	Next entry in use.

Function Documentation

eth_init()

void eth_init

(

uchar *

mac

)

Initialise the ethernet subsystem.

Parameters

[in]

mac

Our MAC address

ipsum()

uint ipsum	(	uchar *	d,
		uint	len,
		uint	sum
	)

Compute an IP checksum.

Parameters

[in]	d	The data to checksum
[in]	len	Number of bytes in data
[in]	sum	Initial value; allows chaining of summing

Returns

the checksum

copy_mac()

void copy_mac	(	const uchar *	f,
		uchar *	t
	)

Copy MAC address.

Parameters

[in]	f	Where to copy from. Must be at least half-word aligned
[out]	t	Where to copy to. Must be at least half-word aligned

copy_ip()

void copy_ip	(	const uchar *	f,
		uchar *	t
	)

Copy IP address.

Parameters

[in]	f	Where to copy from. Must be at least half-word aligned
[out]	t	Where to copy to. Must be at least half-word aligned

cmp_ip()

uint cmp_ip	(	const uchar *	a,
		const uchar *	b
	)

Compare IP addresses.

Parameters

[in]	a	First address to compare
[in]	b	Second address to compare

Returns

True if the addresses are equal, false otherwise

copy_ip_hdr()

void copy_ip_hdr	(	uchar *	dest,
		uint	prot,
		ip_hdr_t *	ip,
		uint	len
	)

Initialise IP header.

Parameters

[in]	dest	Destination address
[in]	prot	Protocol to use
[in,out]	ip	Packet with header to initialise, copying dest into. The payload must have already been placed in the packet.
[in]	len	The length of the payload in the packet.

eth_transmit()

void eth_transmit	(	uchar *	buf,
		uint	len,
		uint	type,
		const uchar *	dest
	)

Transmit ethernet packet.

Parameters

[in,out]	buf	The buffer containing the packet to send. Will have the parts that are the ethernet header modified.
[in]	len	Length of buffer (headers and payload)
[in]	type	The type of ethernet packet to send
[in]	dest	The destination MAC address

eth_transmit2()

void eth_transmit2	(	uchar *	hdr,
		uchar *	buf,
		uint	hdr_len,
		uint	buf_len
	)

Transmit ethernet packet.

Parameters

[in]	hdr	The ethernet header, already prepared.
[in]	buf	The buffer containing the payload to send.
[in]	hdr_len	Length of header, hdr
[in]	buf_len	Length of payload, buf

send_arp_pkt()

void send_arp_pkt	(	uchar *	buf,
		const uchar *	dest,
		const uchar *	tha,
		const uchar *	tpa,
		uint	type
	)

Send an ARP packet.

Parameters

[in,out]	buf	Buffer containing ARP packet. Payload must have been set.
[in]	dest	Destination MAC address
[in]	tha	Target hadrware address
[in]	tpa	Target protocol address
[in]	type	Opcode (e.g., ARP_REQ)

arp_lookup()

void arp_lookup

(

iptag_t *

iptag

)

Initiate ARP lookup if required. Lookup might be immediate (out of cache) or require network traffic.

Parameters

[in,out]

iptag

The IPTag that needs the lookup done. Will be updated with results when available.

arp_pkt()

void arp_pkt	(	uchar *	rx_pkt,
		uint	rx_len,
		uint	tag_table_size
	)

ARP packet received handler.

Parameters

[in]	rx_pkt	The received packet
[in]	rx_len	The length of the received packet
[in]	tag_table_size	How large is our tag table?

arp_add()

void arp_add	(	uchar *	mac,
		uchar *	ip
	)

Add a MAC/IP address binding to our ARP cache.

Parameters

[in]	mac	The MAC address
[in]	ip	The IP address

icmp_pkt()

void icmp_pkt	(	uchar *	rx_pkt,
		uint	rx_len
	)

ICMP packet received handler.

Parameters

[in]	rx_pkt	The received packet
[in]	rx_len	The length of the received packet

copy_udp()

void copy_udp	(	uchar *	buf,
		uint	len,
		uint	dest,
		uint	srce
	)

Initialise UDP packet header.

Parameters

[in,out]	buf	The UDP packet, header and payload. Payload must have been initialised.
[in]	len	Length of payload.
[in]	dest	Destination port.
[in]	srce	Source port.