klibc - Jun 2011 - [PATCH] Don't try to guess the nameserver in ipconfig.

klibcs ipconfig tries to guess the nameserver if no nameserver is
provided. This may happen due to misconfigured dhcp or the use of
the ip= parameter.

This patch removes the guessing from ipconfig as it is not possible for
any other script to determine if the provided nameserver is valid or
a guessed one. If the old behavior is really needed this could be easily
implemented in an external script.

Closes: #594638

Signed-off-by: Ulrich Dangel <uli at spamt.net>
---
 usr/kinit/ipconfig/main.c |    5 -----
 1 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/usr/kinit/ipconfig/main.c b/usr/kinit/ipconfig/main.c
index 4833bb7..0fd35c1 100644
--- a/usr/kinit/ipconfig/main.c
+++ b/usr/kinit/ipconfig/main.c
@@ -176,11 +176,6 @@ static void postprocess_device(struct netdev *dev)
 		printf("IP-Config: %s guessed broadcast address %s\n",
 		       dev->name, my_inet_ntoa(dev->ip_broadcast));
 	}
-	if (dev->ip_nameserver[0] == INADDR_ANY) {
-		dev->ip_nameserver[0] = dev->ip_server;
-		printf("IP-Config: %s guessed nameserver address %s\n",
-		       dev->name, my_inet_ntoa(dev->ip_nameserver[0]));
-	}
 }
 
 static void complete_device(struct netdev *dev)
-- 
1.7.1

On Wed, 08 Jun 2011, Ulrich Dangel wrote:
> klibcs ipconfig tries to guess the nameserver if no nameserver is
> provided. This may happen due to misconfigured dhcp or the use of
> the ip= parameter.
> 
> This patch removes the guessing from ipconfig as it is not possible for
> any other script to determine if the provided nameserver is valid or
> a guessed one. If the old behavior is really needed this could be easily
> implemented in an external script.
> 
> Closes: #594638
> 
> Signed-off-by: Ulrich Dangel <uli at spamt.net>
have to check older linux <= 2.0, haven't seen this guessing
in any newer ones.

Your analysis shows that  ip_nameserver is unused outside of ipconfig,
nor any sign of gethostbyname() or such. mount.c doesn't do dns resolving,
so I'd guess your patch is a welcome fix for 
http://bugs.debian.org/594638
> ---
>  usr/kinit/ipconfig/main.c |    5 -----
>  1 files changed, 0 insertions(+), 5 deletions(-)
> 
> diff --git a/usr/kinit/ipconfig/main.c b/usr/kinit/ipconfig/main.c
> index 4833bb7..0fd35c1 100644
> --- a/usr/kinit/ipconfig/main.c
> +++ b/usr/kinit/ipconfig/main.c
> @@ -176,11 +176,6 @@ static void postprocess_device(struct netdev *dev)
>  		printf("IP-Config: %s guessed broadcast address %s\n",
>  		       dev->name, my_inet_ntoa(dev->ip_broadcast));
>  	}
> -	if (dev->ip_nameserver[0] == INADDR_ANY) {
> -		dev->ip_nameserver[0] = dev->ip_server;
> -		printf("IP-Config: %s guessed nameserver address %s\n",
> -		       dev->name, my_inet_ntoa(dev->ip_nameserver[0]));
> -	}
>  }
>  
>  static void complete_device(struct netdev *dev)
> -- 
> 1.7.1
> 
-- 
maks