IFF_PROMISC, IFF_BROADCAST missing from std.os.linux

[kj4tmp]

These are used when configuring low level network interfaces. More information can be found in man netdevice

Here is a use case of setting the promiscuous and broadcast flags on a network device.

(yes this is currently brutal):

var ifr: std.posix.ifreq = std.mem.zeroInit(std.posix.ifreq, .{});
@memcpy(ifr.ifrn.name[0..ifname.len], ifname);
ifr.ifrn.name[ifname.len] = 0;
try std.posix.ioctl_SIOCGIFINDEX(socket, &ifr);
const ifindex: i32 = ifr.ifru.ivalue;

var rval = std.posix.errno(std.os.linux.ioctl(socket, std.os.linux.SIOCGIFFLAGS, @intFromPtr(&ifr)));
switch (rval) {
    .SUCCESS => {},
    else => {
        return error.NicError;
    },
}
const IFF_PROMISC = 256;
const IFF_BROADCAST = 2;
ifr.ifru.flags = ifr.ifru.flags | IFF_BROADCAST | IFF_PROMISC;
rval = std.posix.errno(std.os.linux.ioctl(socket, std.os.linux.SIOCSIFFLAGS, @intFromPtr(&ifr)));
switch (rval) {
    .SUCCESS => {},
    else => {
        return error.NicError;
    },
}