On 12 July 2012, at 07:24, Matthias Apitz wrote:
>
> 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);
> }
>
>
I won't claim to be an expert on this, but I have used getaddrinfo successfully
in servers. The only thing I see that might be an issue is the use of zero for
ai_protocol. The comment in the man page implies that value is for servers and
not clients. I suspect you have to set the specific protocol you want. You
haven't included AI_PASSIVE so I suspect its expecting you to use the address
to contact a server.
_______________________________________________
freebsd-questions@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
