Conversion Support Function

Functions
char *	inet_ntoa (uint32_t i_addr, char *s)
	Convert IP-address from 0xbbaaddcc to "aaa.bbb.ccc.ddd". More...
uint32_t	inet_aton (char *s)
	Converts zero terminated IP-address string from "aaa.bbb.ccc.ddd" to integer in network byte order. More...
static uint16_t	htons (uint16_t val)
	Convert a short int from host to network byte order. More...
static uint16_t	ntohs (uint16_t val)
	Convert a short int from network to host byte order. More...
static uint32_t	htonl (uint32_t val)
	Convert a long int from host to network byte order. More...
static uint32_t	ntohl (uint32_t val)
	Convert a long int from network to host byte order. More...
static uint32_t	nstohl (uint16_t val1, uint16_t val2)
	Convert two network short int to long host int. More...
static uint32_t	nstonl (uint16_t val1, uint16_t val2)
	Convert two network short int to long. More...

Detailed Description

Function Documentation

char * inet_ntoa	(	uint32_t	i_addr,
		char *	s
	)

Parameters

i_addr	- IP address in network-byte-order
s	- buffer space for conversion

Returns

pointer to converted buffer

Convert IP address from network byte order to zero terminated ASCII string.
Usually all IP addresses in a network are stored and processed in network byte order. If the IP address of a specific connection should be printed out, use this conversion function.

Warning

Make sure the destination buffer is large enough to hold 16 characters (including terminating zero).

Library:

net.lib

Prototype:

net.h

//**************************************************************************
// print DSP IP address after DHCP request
//**************************************************************************
u_int32_t ip;
char buffer[20];  // small buffer for ip-address conversion

ip = get_ip_address (0);
printf (" assigned DSP IP-address: %s\r\n", inet_ntoa (ip, buffer));

Examples:

Blocksend.c, DHCPTest.c, DNSTest.c, Echo.c, FTPServer.c, Multicast.c, NetTest.c, Send.c, SMTP.c, and Telnet.c.

uint32_t inet_aton

(

char *

s

)

Parameters

s	- ip address string

Returns

ip address in network byte order

Convert IP address string to network byte order.
Use this function to initialize a destination IP address before UDP send or to invalidate the ARP cache.

Note

Supported class delimiters are '.' and ','.

Library:

net.lib

Prototype:

net.h

arp_invalid_ip_address (inet_aton("192.168.168.8"));

static inline uint16_t htons ( uint16_t  val )

inlinestatic

Parameters

val	- short int to convert

Returns

converted short int

Convert a short int from host to network byte order

Prototype:

net.h

Examples:

BoardSpecific.c.

{
    return ((uint16_t)((((val) & 0xff) << 8) | ((val) & 0xff00) >> 8));
}

static inline uint16_t ntohs ( uint16_t  val )

inlinestatic

Parameters

val	- short int to convert

Returns

converted short int

Convert a short int from network to host byte order

Prototype:

net.h

{
    return ((uint16_t)((((val) & 0xff) << 8) | ((val) & 0xff00) >> 8));
}

static inline uint32_t htonl ( uint32_t  val )

inlinestatic

Parameters

val	- long int to convert

Returns

converted long int

Convert a long int from host to network byte order

Prototype:

net.h

{
    return ((uint32_t) ((((val) & 0xff)       << 24  ) |
                        (((val) & 0xff00)     << 8   ) |
                        (((val) & 0xff0000)   >> 8   ) |
                         ((val) & 0xff000000) >> 24));
}

static inline uint32_t ntohl ( uint32_t  val )

inlinestatic

Parameters

val	- long int to convert

Returns

converted long int

Convert a long int from network to host byte order

Prototype:

net.h

{
    return ((uint32_t) ((((val) & 0xff)       << 16  ) |
                        (((val) & 0xff00)     << 16  ) |
                        (((val) & 0xff0000)   >> 16  ) |
                         ((val) & 0xff000000) >> 16  ));
}

static inline uint32_t nstohl ( uint16_t  val1, uint16_t  val2  )

inlinestatic

Parameters

val1	- high word
val2	- low word

Returns

converted long int

Convert two network short int to long host int

Prototype:

net.h

{
    return( (uint32_t) ( (((uint32_t)(val1) & 0xff)   << 24 ) |
                         (((uint32_t)(val1) & 0xff00) << 8 )  |
                         (((uint32_t)(val2) & 0xff)   << 8  ) |
                         (((uint32_t)(val2) & 0xff00) >> 8 ) ) );
}

static inline uint32_t nstonl ( uint16_t  val1, uint16_t  val2  )

inlinestatic

Parameters

val1	- high word
val2	- low word

Returns

converted long int

Convert two network short int to long

Prototype:

net.h

{
    return ((uint32_t)((((uint32_t)(val1) & 0xffff) << 16 ) |
                        ((uint32_t)(val2) & 0xffff) ));
}