Generic DNS values. More...

Detailed Description

Generic DNS values.

Modules
	DNS cache
	DNS cache.

	DNS message parser and composer
	Parsing and composition of DNS messages.

Files
file	dns.h
	Generic DNS values.

Functions
static int	dns_query (const char domain_name, void addr_out, int family)
	Get IP address for DNS name.

DNS defines
#define	DNS_TYPE_A (1)

#define	DNS_TYPE_AAAA (28)

#define	DNS_CLASS_IN (1)

Field lengths
#define	RR_TYPE_LENGTH (2U)

#define	RR_CLASS_LENGTH (2U)

#define	RR_TTL_LENGTH (4U)

#define	RR_RDLENGTH_LENGTH (2U)

Macro Definition Documentation

◆ DNS_CLASS_IN

#define DNS_CLASS_IN (1)

Definition at line 38 of file dns.h.

◆ DNS_TYPE_A

#define DNS_TYPE_A (1)

Definition at line 36 of file dns.h.

◆ DNS_TYPE_AAAA

#define DNS_TYPE_AAAA (28)

Definition at line 37 of file dns.h.

◆ RR_CLASS_LENGTH

#define RR_CLASS_LENGTH (2U)

Definition at line 46 of file dns.h.

◆ RR_RDLENGTH_LENGTH

#define RR_RDLENGTH_LENGTH (2U)

Definition at line 48 of file dns.h.

◆ RR_TTL_LENGTH

#define RR_TTL_LENGTH (4U)

Definition at line 47 of file dns.h.

◆ RR_TYPE_LENGTH

#define RR_TYPE_LENGTH (2U)

Definition at line 45 of file dns.h.

Function Documentation

◆ dns_query()

static int dns_query	(	const char *	domain_name,
		void *	addr_out,
		int	family
	)

inlinestatic

Get IP address for DNS name.

This function will synchronously try to resolve a DNS A or AAAA record by contacting the DNS server specified in the global variable sock_dns_server.

By supplying AF_INET, AF_INET6 or AF_UNSPEC in family requesting of A records (IPv4), AAAA records (IPv6) or both can be selected.

This function will return the first DNS record it receives. IF both A and AAAA are requested, AAAA will be preferred.

Note: addr_out needs to provide space for any possible result! (4byte when family==AF_INET, 16byte otherwise)

Parameters

[in]	domain_name	DNS name to resolve into address
[out]	addr_out	buffer to write result into
[in]	family	Either AF_INET, AF_INET6 or AF_UNSPEC

Returns: the size of the resolved address on success; < 0 otherwise

Definition at line 73 of file dns.h.

Detailed Description

Modules

Files

Functions

DNS defines

Field lengths