Giacomo,
Consider using the dev_get_by_name/() kernel method; this is a
simplified example which works with device named "eth0" :
struct net_device* device;
struct in_device* in_dev;
struct in_ifaddr* if_info;
device = dev_get_by_name("eth0");
in_dev = (struct in_device *)device->ip_ptr;
if_info = in_dev->ifa_list;
for (;if_info;if_info=if_info->ifa_next)
{
if (!(strcmp(if_info->ifa_label,"eth0")))
{
printk("if_info->ifa_address=%x\n",if_info->ifa_address);
break;
}
}
Yous should of course add check for NULL, etc.
Regards,
Rami Rosen
On Nov 20, 2007 10:09 AM, Giacomo <[EMAIL PROTECTED]> wrote:
> Good morning.
>
> I have written a kernel function which needs to get the IP address of
> an active network interface
> given its name.
>
> The actual implementation i have done is like this
> but i suspect this does not always work.
> Is there any API already provided by the kernel to do the same?
>
> Thanks a lot
>
> Giacomo
>
> -- actual implementation: ---
>
> /* returns in *addr the internet address having the name ifname */
> int get_ifaddr_by_name(const char *ifname, __u32 * addr)
> {
> struct net_device *pnet_device;
> struct in_device *pin_device;
> struct in_ifaddr* inet_ifaddr;
>
> read_lock_bh(&dev_base_lock);
> #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
> pnet_device = dev_base;
> #else
> pnet_device = first_net_device();
> #endif
> while (pnet_device != NULL)
> {
> if ((netif_running(pnet_device))
> && (pnet_device->ip_ptr != NULL)
> && (strcmp(pnet_device->name, ifname) == 0))
> {
> pin_device =
> (struct in_device *) pnet_device->ip_ptr;
> inet_ifaddr = pin_device->ifa_list;
> if(inet_ifaddr == NULL)
> {
> printk("ifa_list is null!\n");
> break;
> }
> /* ifa_local: ifa_address is the remote point in ppp
> */
> *addr = (inet_ifaddr->ifa_local);
> read_unlock_bh(&dev_base_lock);
> return 1;
> }
> #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
> pnet_device = pnet_device->next;
> #else
> pnet_device = next_net_device(pnet_device);
> #endif
>
> }
>
> read_unlock_bh(&dev_base_lock);
> return -1; /* address not found! */
> }
>
> --
> Giacomo S.
> http://www.giacomos.it
>
> - - - - - - - - - - - - - - - - - - - - - -
>
> IPFIREwall (http://www.giacomos.it/ipfire) viene presentato
> all'Universita` degli Studi di Udine, il 28 ottobre, in occasione del
> Linux Day 2006:
> http://iglu.cc.uniud.it/linuxday
>
> - - - - - - - - - - - - - - - - - - - - - -
>
> . '' `.
> : :' :
> `. ` '
> `- Debian GNU/Linux -- The power of freedom
> http://www.debian.org
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