Check if TCP segmentation has been offloaded for a particular interface

Question

I know we can check through ethtool whether TCP segmentation has been offloaded. But I need to get this info from my own code. What is the simplest way to do this? Is there a flag that I can check for this?

Thanks Supreeth

Answer 1

You can use the same ioctl() call as ethtool does. Just look at the source code for ethtool to figure out how it does it:

struct ethtool_value eval;

eval.cmd = ETHTOOL_GGSO;
ifr->ifr_data = (caddr_t)&eval;
err = ioctl(fd, SIOCETHTOOL, ifr);
if (err)
        perror("Cannot get device generic segmentation offload settings");
else {
        gso = eval.data;
        allfail = 0;
}