udhcpd not starting

[Denys Vlasenko]

On Thursday 08 October 2009 14:11, Ruben Lagar wrote:
> Hello everybody,
> I have successfully cross-compiled busybox for an arm processor. Now I am
> trying to run udhcpd with a very basic config file
> 
> 
> *start ** **10.0.1.100** *
> *end** **10.0.1.120** *
> *interface** **usb0** *
> *max_leases** **21** *
> *lease_file** **/etc/udhcpd.leases** *
> *pidfile** **/etc/udhcpd.pid** *
> *option** **subnet** **255.255.255.0*
> *option** **domain** **local*
> *option** **lease** **864000*
> 
> But when I try to run it, I get an error:
> 
> udhcpd (v1.14.1) started
> *udhcpd: can't bind to interface usb0: Protocol not available*
> 
> I have been Googling it, and it looks like some Kernel problem or similar,
> but haven't found exactly what is going on.
> 
> Has anyone get this error before? Is there any way around it?

Here is where it comes from:

int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface)
{
        int r;
        struct ifreq ifr;
        strncpy_IFNAMSIZ(ifr.ifr_name, iface);
        /* NB: passing (iface, strlen(iface) + 1) does not work!
         * (maybe it works on _some_ kernels, but not on 2.6.26)
         * Actually, ifr_name is at offset 0, and in practice
         * just giving char[IFNAMSIZ] instead of struct ifreq works too.
         * But just in case it's not true on some obscure arch... */
        r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
        if (r)
                bb_perror_msg("can't bind to interface %s", iface);
        return r;
}

A few shots in the dark:

(1) Is af_packet built (CONFIG_FILTER=y/m)? If it's a module (m, not y),
    is it inserted?
(2) Do you run udhcpd as root?
(3) Try adding "memset(&ifr, 0, sizeof(ifr));" before strncpy_IFNAMSIZ.

--
vda