Re: [lwip-users] How to determine if DCHP changes the IP address

[Jonathan Larmour]

Bill Auerbach wrote:
> Thank you, great.  I’m glad it’s been done already.
> 
>  
> 
> No, it’s not in 1.2.0 – not that I see.

For 1.2.0 I used something like:

#include "lwip/netif.h"

#if 1
netif = netif_default;
#else
netif = netif_find("e0"); /* Get netif for i/f e0 */
#endif
if (netif)
{
    u32_t haddr = ntohl(netif->ip_addr.addr);
    printf("lwIP default i/f[%c%c]: IP %d.%d.%d.%d\n",
           netif->name[0], netif->name[1],
           (int)((haddr >> 24) & 0xff),
           (int)((haddr >> 16) & 0xff),
           (int)((haddr >>  8) & 0xff),
           (int)((haddr >>  0) & 0xff));
} else {
    printf("No lwip i/f found\n");
}

Theoretically this could be subject to problems in a dynamic system, should
the interface go down or get deleted. Personally I was using this code just
after DHCP would have been completed, and in the context of my application,
it wouldn't have gone down, so for me it was safe.

Jifl
-- 
eCosCentric Limited      http://www.eCosCentric.com/     The eCos experts
Barnwell House, Barnwell Drive, Cambridge, UK.       Tel: +44 1223 245571
Registered in England and Wales: Reg No 4422071.
------["Si fractum non sit, noli id reficere"]------       Opinions==mine