I am using following structure, it is defined in net/if.h.

struct ifreq        ifr;
ifr.ifr_flags = ifr.ifr_flags | IFF_PROMISC;

When I compile my application following errors displayed,

 error: storage size of 'ifr' isn't known
 error: invalid application of 'sizeof' to incomplete type 'struct ifreq'
error: 'IFF_PROMISC' undeclared (first use in this function)
 error: invalid application of 'sizeof' to incomplete type 'struct ifreq'
 error: invalid application of 'sizeof' to incomplete type 'struct ifreq'
 error: invalid application of 'sizeof' to incomplete type 'struct ifreq'

And also I would like to  get interface hw address, somebody suggested to use getifaddrs(), freeifaddrs() because 
SIOCGIFHWADDR is not supported in QNX, Can anybody give me the sample code for the same.

Thanks,
Vinod.