IPv6 && getaddrinfo(3C)

[Matthias Apitz]

Hello,

I'm playing around with IPv6 code on a FreeBSD 9 system and can't get
getaddrinfo(3C) to do what it should do as stated in its man page:
accept an IPv6 and IPv4 IP addr, it only works with the IPv6 form:

$ ./a.out ::1
host: ::1
read: SSH-2.0-OpenSSH_5.6p1 FreeBSD-20101111
$ ./a.out 127.0.0.1
host: 127.0.0.1
ssh: getaddrinfo failed code 8: hostname nor servname provided, or not known
$ telnet 127.0.0.1 22
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
SSH-2.0-OpenSSH_5.6p1 FreeBSD-20101111

the used C-code is attached below; what I'm doing wrong in the code?

Thanks

	matthias

/* IPv6 client code using getaddrinfo */

#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <netdb.h>
#include <string.h>


main(argc, argv)		/* client side */
	int		argc;
	char           *argv[];
{

	struct addrinfo	req, *ans;
	int	code, s, n;
	char buf[1024];

	memset(&req, 0, sizeof(req));
	req.ai_flags = AI_ADDRCONFIG|AI_NUMERICHOST;
	req.ai_family = AF_INET6;	/* Same as AF_INET6. */
	req.ai_socktype = SOCK_STREAM;

	/*                                         */
	/* Use default protocol (in this case tcp) */
	/*                                         */

	req.ai_protocol = 0;

	printf("host: %s\n", argv[1]);
	if ((code = getaddrinfo(argv[1], "ssh", &req, &ans)) != 0) {
		fprintf(stderr, "ssh: getaddrinfo failed code %d: %s\n", code, gai_strerror(code));
		exit(1);
	}
	 
	 
	/*                                             */
	/* ans must contain at least one addrinfo, use */
	/* the first.                                  */
	/*                                             */ 
	
	s = socket(ans->ai_family, ans->ai_socktype, ans->ai_protocol);
	if (s < 0) {
		perror("ssh: socket");
		exit(3);
	}

	/* Connect does the bind for us */
	
	if (connect(s, ans->ai_addr, ans->ai_addrlen) < 0) {
		perror("ssh: connect");
		exit(5);
	}

	n = read(s, buf, 1024);
	printf ("read: %s", buf);
	
	/* */
	/* Free answers after use */
	/* */ 
	freeaddrinfo(ans);

	exit(0);
}


-- 
Matthias Apitz
e <guru at unixarea.de> - w http://www.unixarea.de/
UNIX since V7 on PDP-11, UNIX on mainframe since ESER 1055 (IBM /370)
UNIX on x86 since SVR4.2 UnixWare 2.1.2, FreeBSD since 2.2.5