sa_family_t is a uint8_t on Darwin but unsigned short on Linux

[djs55]

On Darwin we have:

typedef __uint8_t               sa_family_t;

struct sockaddr_in {
        __uint8_t       sin_len;
        sa_family_t     sin_family;
        in_port_t       sin_port;
        struct  in_addr sin_addr;
        char            sin_zero[8];
};

> #define AF_UNIX         1               /* local to host (pipes) */
> #define AF_LOCAL        AF_UNIX         /* backward compatibility */
> #define AF_INET         2               /* internetwork: UDP, TCP, etc. */
> #define AF_INET6        30              /* IPv6 */

On Linux we have:

typedef unsigned short sa_family_t;

struct sockaddr_in {
	sa_family_t sin_family;
	in_port_t sin_port;
	struct in_addr sin_addr;
	uint8_t sin_zero[8];
};

> #define PF_LOCAL        1
> #define PF_UNIX         PF_LOCAL
> #define AF_LOCAL        PF_LOCAL
> #define PF_INET         2
> #define PF_INET6        10
> #define AF_INET         PF_INET
> #define AF_INET6        PF_INET6

Since the relevant constants are all small, I think it's ok to use a uint8_t on both platforms. I'm not a Ctypes expert though, so there might be a better way.

Fixes #111

[aantron]

@djs55 Thanks for looking into that, I would not have found it, as I am on Linux!

The fix in this PR would break access for the family field on big-endian platforms. Can you try the alternative fix, branch sa_family_t in this repo?

[djs55]

@aantron your alternative fix works fine for me. I can call Luv.TCP.getsockname and query the bound IP and port as expected on macOS. Thanks!

[aantron]

Thanks. I've merged that fix into master. Going to close this PR in favor of it, and do a release.

[avsm]

My (forthcoming) S390x OCaml tests thank you for your consideration of big-endian architectures :-)