dns_helpers.c File Reference

DNS helper functions that do no network actions. More...

#include <qdns.h>
#include <arpa/inet.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>

Functions
int	domainvalid (const char *const host)
void	freeips (struct ips *p)
static int	ip6_sort (const void *l, const void *r)
void	sortmx (struct ips **p)
	sort MX list by priority More...
struct ips *	in6_to_ips (struct in6_addr *a, unsigned int cnt, const unsigned int priority)
	convert an array of in6_addr structs to a list of struct ips More...
int	inet_pton_v4mapped (const char *str, struct in6_addr *addr)
	read an IPv4 address and convert it to a v4mapped IPv6 address More...

Detailed Description

DNS helper functions that do no network actions.

Function Documentation

int domainvalid

(

const char *const

host

)

check if a string is a valid fqdn

Parameters

host	the name to check

Returns

if the string is a valid domain name

Return values

0	everything is ok
1	on syntax error

if there is a standard function doing the same throw this one away

void freeips

(

struct ips *

p

)

free memory of IP list

Parameters

p	IP list to free

struct ips* in6_to_ips	(	struct in6_addr *	a,
		unsigned int	cnt,
		const unsigned int	priority
	)

convert an array of in6_addr structs to a list of struct ips

Parameters

a	the input array
cnt	the address count in a (must be >0)
priority	priority of the new records

Returns

list of struct ips

Return values

NULL	an allocation error happened during conversion

a will always be freed.

int inet_pton_v4mapped	(	const char *	str,
		struct in6_addr *	addr
	)

read an IPv4 address and convert it to a v4mapped IPv6 address

Parameters

str	the string to read in
addr	where to store the resulting address

Returns

the same values as inet_pton()

Return values

1	address was successfully read in

void sortmx

(

struct ips **

p

)

sort MX list by priority

Parameters

p	list of MX entries

Inside each entry of p the IPv6 entries are moved to the front so that IPv6 addresses are prefered. If 2 entries of p have the same priority those that contain IPv6 addresses will be moved to the front for the same reason.

If IPV4ONLY is defined all IPv6 addresses will be stripped from the list.