[SOLVED] read function call failing with EFAULT (Bad address)

chakka.lokesh · 09-12-2014, 04:23 AM

I want to receive any packet with any destination/source ethernet address.

I set the card in promiscous mode using the following code:

Code:

ifr.ifr_flags |= ( IFF_PROMISC );
ioctl( sockets, SIOCSIFFLAGS, &ifr )

ioctl has returned success.

still I am seeing read function is returning EFAULT error.

Is it okay if I ignore that error and do call the read function again with same parameters ?

can some one please help me in fixing the issue ?

berndbausch · 09-12-2014, 05:20 AM

Quote:

Originally Posted by chakka.lokesh

still I am seeing read function is returning EFAULT error.

This is unlikely to be related to the ioctl() call.

From the read(2) man page:

Quote:

ssize_t read(int fd, void *buf, size_t count);
[.....]
EFAULT - buf is outside your accessible address space

In your case, buf might be a NULL pointer, or too small for what you are reading, or pointing to an unallocated address.