I am writing an application that reports attributes of network devices on the local machine. I need the mac address, mtu, link speed and a few others. I'm using udev for this. I've already figured out how to get the mac address and mtu, but not how to get the link speed. I can get it with ethtool from the terminal, but I need a way to get it programmatically.
Does anyone know how I can get the link speed attribute with udev or another library?
You need to use the SIOCETHTOOL ioctl() call. There's a nice introduction to ioctl/SIOCETHTOOL call on LinuxJournal, and the code below (which is not intended to be an example of good C practices!) should show you how to use it to get the speed.
#include #include #include #include #include #include #include #include #include int main (int argc, char **argv) { int sock; struct ifreq ifr; struct ethtool_cmd edata; int rc; sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); if (sock