[PATCH v2 5/6] common: state: Add function to read state MAC

[Sascha Hauer]

On Thu, Nov 02, 2017 at 01:42:44PM +0100, Daniel Schultz wrote:
> This API function allows to receive a copy of a MAC address from
> variables in a state.
> 
> Signed-off-by: Daniel Schultz <d.schultz at phytec.de>
> ---
> Changes:
> 	v2: New patch
> 
>  common/state/state.c | 23 +++++++++++++++++++++++
>  include/state.h      |  2 ++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/common/state/state.c b/common/state/state.c
> index 266d211..063e03e 100644
> --- a/common/state/state.c
> +++ b/common/state/state.c
> @@ -693,6 +693,29 @@ int state_get_name(const struct state *state, char const **name)
>  	return 0;
>  }
>  
> +int state_read_mac(struct state *state, const char *name, u8 *buf)
> +{
> +	struct state_variable *svar;
> +	struct state_mac *mac;
> +	int i;
> +
> +	if (!state || !name || !buf)
> +		return -EINVAL;
> +
> +	svar = state_find_var(state, name);
> +	if (IS_ERR(svar))
> +		return PTR_ERR(svar);
> +
> +	if (!strcmp(svar->type->type_name, "mac")) {

Could you add a patch before this one that adds a

enum state_variable_type {
	STATE_VARIABLE_TYPE_UINT8,
	...
};

Then add the type to struct variable_type and test for the type
rather than for the string name? I think in the longer run this will be
nicer when we get additional tests for the variable_type.

> +		mac = to_state_mac(svar);
> +		for (i = 0; i < 6; i++)
> +			buf[i] = mac->value[i];

memcpy?

> +		return 6;

So '6' is the return value for successfully calling this function. This
is the length of the MAC Address, but does this add any value? Better
use a negative error code and '0' for success.

Sascha

> +	}
> +
> +	return 0;
> +}
> +

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