Re: autoip address set/reset loop

[John Keeping <john@metanate.com>]

On Wed, Nov 23, 2022 at 03:56:42PM +0100, Geoffrey Van Landeghem wrote:
> Subject: Re: autoip address set/reset loop
> 
> Here is the patch:
> 
> From b7750b925714572cba12275e6da49b8b70cd3fbb Mon Sep 17 00:00:00 2001
> From: Geoffrey Van Landeghem <geoffrey.vl@gmail.com>
> Date: Tue, 22 Nov 2022 19:50:12 +0100
> Subject: [PATCH] ipconfig: revert not adding invalid gateway routes
> 
> ---
>  src/ipconfig.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/src/ipconfig.c b/src/ipconfig.c
> index 74215e1d..875819a0 100644
> --- a/src/ipconfig.c
> +++ b/src/ipconfig.c
> @@ -1183,13 +1183,17 @@ int __connman_ipconfig_gateway_add(struct connman_ipconfig *ipconfig)
>  
>  	DBG("");
>  
> -	if (!ipconfig->address || !ipconfig->address->gateway)
> +	if (!ipconfig->address)
>  		return -EINVAL;
>  
>  	service = __connman_service_lookup_from_index(ipconfig->index);
>  	if (!service)
>  		return -EINVAL;
>  
> +	/*
> +	 * Gateway is allowed to be NULL here, see
> +	 * __connman_connection_gateway_add()
> +	 */
>  	DBG("type %d gw %s peer %s", ipconfig->type,
>  		ipconfig->address->gateway, ipconfig->address->peer);

If gateway can be null you need to make sure the argument to DBG() is
non-null.  While glibc handles null for %s other C libraries may crash.