[En-Nut-Discussion] DNS server IP via DHCP

[Hugo Simon]

Hi,

I had the same problem and it seems there is no official way to get that
info. So I investigated a bit. The NutDnsConfig2 routine stores the setting
in a global but private structure "doc". So the simpliest way is to make
that structure public.

I moved it's definition from "pro/resolv.c" to "netdb.h"

So in "pro/resolv.c" the only thing is to remove the type definition and
therefor include the netdb.h:
-----------------------------------------------------
/*
 * moved to netdb.h, so everyone can get the current DNS parameters
typedef struct {
    u_char *doc_hostname;
    u_char *doc_domain;
    u_long doc_ip1;
    u_long doc_ip2;
} DNSCONFIG;
*/
DNSCONFIG doc;
-----------------------------------------------------


Then put it into "netdb.h"
-----------------------------------------------------
typedef struct {
    u_char *doc_hostname;
    u_char *doc_domain;
    u_long doc_ip1;
    u_long doc_ip2;
} DNSCONFIG;

extern DNSCONFIG doc;
-----------------------------------------------------

Now you can access it from everywhere in your code by writing

printf("Hostname : %s.%s\n", doc.doc_hostname, doc.doc_domain);
printf("Primary DNS server  : %s\n", inet_ntoa(doc.doc_ip1);
printf("Secondary DNS server: %s\n", inet_ntoa(doc.doc_ip2);

But beware. If there is nothing configured the pointers to hostname and
domain are set to NULL. So check before using it.

I hope that helps. I used an old 3.4.2.1 of NutOS. Maybe it's different in
the actual 3.9x version.

bye
Thorsten


> I've looked at the standard DHCP code and see that it retrieves the DNS
> Server settings from the DHCP server and configures them using
> NutDnsConfig2.
>
> This is good. However, I want to "display" these values retrieved from the
> DHCP request (and others if possible). Does anyone know how to access
these
> field other tahn modifying the dhcp code ?