Re: getaddrinfo: DNS round robin vs RFC3484 s6 rule 9, for etch

[Kurt Roeckx <kurt@roeckx.be>]

On Sat, Sep 29, 2007 at 02:07:02PM +0200, Wolf Wiegand wrote:
> 
> The machine I have access to doesn't support ahosts. getent host 
> returns different addresses for ftp.us.debian.org on subsequent calls.

Please either try this python script:
import socket
k = [ socket.getaddrinfo("rule9.erisian.com.au", "http")[0][4][0] for blah in range(1000) ]
print dict([ (l, k.count(l)) for l in k ])


Or compile the attached C file and run it multiple times.


Kurt

#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>

int main()
{
	struct addrinfo *res, *p, hints;

	hints.ai_flags = 0;
	hints.ai_family = PF_UNSPEC;
	hints.ai_socktype = SOCK_DGRAM;
	hints.ai_protocol = 0;
	hints.ai_addrlen = 0;
	hints.ai_addr = NULL;
	hints.ai_canonname = NULL;
	hints.ai_next = NULL;

	getaddrinfo("0.pool.ntp.org", "ntp", &hints, &res);

	for (p = res; p; p = p->ai_next)
	{
		if (p->ai_family == AF_INET)
		{
			char ip[INET_ADDRSTRLEN];
			if (inet_ntop(p->ai_family,
				&(*(struct sockaddr_in *)p->ai_addr).sin_addr,
				ip, sizeof(ip)) != NULL)
			{
				printf("%s\n", ip);
			}
		}
	}
	freeaddrinfo(res);
	return 0;
}