openSocketPosix

fn openSocketPosix(
    k: *Kqueue,
    family: posix.sa_family_t,
    options: IpAddress.BindOptions,
) error{
    AddressFamilyUnsupported,
    ProtocolUnsupportedBySystem,
    ProcessFdQuotaExceeded,
    SystemFdQuotaExceeded,
    SystemResources,
    ProtocolUnsupportedByAddressFamily,
    SocketModeUnsupported,
    OptionUnsupported,
    Unexpected,
    Canceled,
}!posix.socket_t {
    const mode, const protocol = try posixSocketModeProtocol(family, options.mode, options.protocol);
    const socket_fd = while (true) {
        try k.checkCancel();
        const flags: u32 = mode | if (Io.Threaded.socket_flags_unsupported) 0 else posix.SOCK.CLOEXEC;
        const socket_rc = posix.system.socket(family, flags, protocol);
        switch (posix.errno(socket_rc)) {
            .SUCCESS => {
                const fd: posix.fd_t = @intCast(socket_rc);
                errdefer closeFd(fd);
                if (Io.Threaded.socket_flags_unsupported) {
                    while (true) {
                        try k.checkCancel();
                        switch (posix.errno(posix.system.fcntl(fd, posix.F.SETFD, @as(usize, posix.FD_CLOEXEC)))) {
                            .SUCCESS => break,
                            .INTR => continue,
                            .CANCELED => return error.Canceled,
                            else => |err| return posix.unexpectedErrno(err),
                        }
                    }

                    var fl_flags: usize = while (true) {
                        try k.checkCancel();
                        const rc = posix.system.fcntl(fd, posix.F.GETFL, @as(usize, 0));
                        switch (posix.errno(rc)) {
                            .SUCCESS => break @intCast(rc),
                            .INTR => continue,
                            .CANCELED => return error.Canceled,
                            else => |err| return posix.unexpectedErrno(err),
                        }
                    };
                    fl_flags |= @as(usize, 1 << @bitOffsetOf(posix.O, "NONBLOCK"));
                    while (true) {
                        try k.checkCancel();
                        switch (posix.errno(posix.system.fcntl(fd, posix.F.SETFL, fl_flags))) {
                            .SUCCESS => break,
                            .INTR => continue,
                            .CANCELED => return error.Canceled,
                            else => |err| return posix.unexpectedErrno(err),
                        }
                    }
                }
                break fd;
            },
            .INTR => continue,
            .CANCELED => return error.Canceled,

            .AFNOSUPPORT => return error.AddressFamilyUnsupported,
            .INVAL => return error.ProtocolUnsupportedBySystem,
            .MFILE => return error.ProcessFdQuotaExceeded,
            .NFILE => return error.SystemFdQuotaExceeded,
            .NOBUFS => return error.SystemResources,
            .NOMEM => return error.SystemResources,
            .PROTONOSUPPORT => return error.ProtocolUnsupportedByAddressFamily,
            .PROTOTYPE => return error.SocketModeUnsupported,
            else => |err| return posix.unexpectedErrno(err),
        }
    };
    errdefer closeFd(socket_fd);

    if (options.ip6_only) |ip6_only| {
        if (posix.IPV6 == void) return error.OptionUnsupported;
        try setSocketOption(k, socket_fd, posix.IPPROTO.IPV6, posix.IPV6.V6ONLY, @intFromBool(ip6_only));
    }

    return socket_fd;
}