Toeplitz hash

Overview

Definition of API to calculate hash used by RSS

// typedefs

typedef struct te_toeplitz_hash_cache te_toeplitz_hash_cache;
typedef enum te_toeplitz_hash_variant te_toeplitz_hash_variant;

// enums

enum te_toeplitz_hash_variant;

// global functions

uint32_t te_toeplitz_hash_data(const te_toeplitz_hash_cache* toeplitz_hash_cache, const uint8_t* input, unsigned int pos, unsigned int datalen);
uint32_t te_toeplitz_hash(const te_toeplitz_hash_cache* toeplitz_hash_cache, unsigned int addr_size, const uint8_t* src_addr, uint16_t src_port, const uint8_t* dst_addr, uint16_t dst_port);
te_errno te_toeplitz_hash_sa(const te_toeplitz_hash_cache* toeplitz_hash_cache, const struct sockaddr* src_addr, const struct sockaddr* dst_addr, te_toeplitz_hash_variant hash_var, uint32_t* hash_out);
uint32_t te_toeplitz_hash_sym_or_xor(const te_toeplitz_hash_cache* toeplitz_hash_cache, unsigned int addr_size, const uint8_t* src_addr, uint16_t src_port, const uint8_t* dst_addr, uint16_t dst_port);
void te_toeplitz_hash_fini(te_toeplitz_hash_cache* toeplitz_hash_cache);
te_toeplitz_hash_cache* te_toeplitz_cache_init(const uint8_t* key);
te_toeplitz_hash_cache* te_toeplitz_cache_init_size(const uint8_t* key, size_t key_size);

Detailed Documentation

Definition of API to calculate hash used by RSS

Typedefs

typedef enum te_toeplitz_hash_variant te_toeplitz_hash_variant

Known variants of Toeplitz hash algorithm

Global Functions

uint32_t te_toeplitz_hash_data(const te_toeplitz_hash_cache* toeplitz_hash_cache, const uint8_t* input, unsigned int pos, unsigned int datalen)

Calculate a Toeplitz hash of input data

Parameters:

toeplitz_hash_cache	Pre-constructed cache
input	Pointer to input data
pos	Position of input data
datalen	Length of input data in bytes
RSS	hash value of input data

uint32_t te_toeplitz_hash(const te_toeplitz_hash_cache* toeplitz_hash_cache, unsigned int addr_size, const uint8_t* src_addr, uint16_t src_port, const uint8_t* dst_addr, uint16_t dst_port)

Calculate a RSS hash using pre-calculated cache

Parameters:

toeplitz_hash_cache	Pre-constructed cache
addr_size	IPv4 / IPv6 address length
src_addr	Pointer to source address
src_port	Source port number in network byte order
dst_addr	Pointer to destination address
dst_port	Desination port number in network byte order
RSS	hash value

te_errno te_toeplitz_hash_sa(const te_toeplitz_hash_cache* toeplitz_hash_cache, const struct sockaddr* src_addr, const struct sockaddr* dst_addr, te_toeplitz_hash_variant hash_var, uint32_t* hash_out)

Calculate a RSS hash for address/port pairs using pre-calculated cache.

Parameters:

toeplitz_hash_cache	Pre-constructed cache
src_addr	Source address/port
dst_addr	Destination address/port
hash_var	Hash variant
hash_out	Where to save computed hash

Returns:

Status code

uint32_t te_toeplitz_hash_sym_or_xor(const te_toeplitz_hash_cache* toeplitz_hash_cache, unsigned int addr_size, const uint8_t* src_addr, uint16_t src_port, const uint8_t* dst_addr, uint16_t dst_port)

Calculate a RSS hash using pre-calculated cache and symmetric algorithm with OR and XOR.

Parameters:

toeplitz_hash_cache	Pre-constructed cache
addr_size	IPv4 / IPv6 address length
src_addr	Pointer to source address
src_port	Source port number in network byte order
dst_addr	Pointer to destination address
dst_port	Desination port number in network byte order

Returns:

RSS hash value.

void te_toeplitz_hash_fini(te_toeplitz_hash_cache* toeplitz_hash_cache)

Free pre-constructed cache

Parameters:

toeplitz_hash_cache

Pointer to cache

te_toeplitz_hash_cache* te_toeplitz_cache_init(const uint8_t* key)

Pre-construct cache to use it for faster calculating of hash used by Toeplitz hash function

Parameters:

key	40-byte hash key
cache	or NULL in case of error

te_toeplitz_hash_cache* te_toeplitz_cache_init_size(const uint8_t* key, size_t key_size)

Pre-construct cache to use it for faster calculation of Toeplitz hash function.

Parameters:

key	Hash key
key_size	Length of the key in bytes
cache	or NULL in case of error