[apparmor] [PATCH v2 20/42] parser: Add features comparison function

[John Johansen]

On 03/06/2015 01:48 PM, Tyler Hicks wrote:
> This is a simple aa_features equality test. Placing it behind a function
> call allows us to do something more complex than a simple string
> comparison later.
> 
> Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
Acked-by: John Johansen <john.johansen at canonical.com>

> ---
>  parser/features.c     | 13 +++++++++++++
>  parser/features.h     |  1 +
>  parser/policy_cache.c |  5 +----
>  3 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/parser/features.c b/parser/features.c
> index 2b81564..07d6e6c 100644
> --- a/parser/features.c
> +++ b/parser/features.c
> @@ -286,3 +286,16 @@ const char *aa_features_get_string(aa_features *features)
>  {
>  	return features->string;
>  }
> +
> +/**
> + * aa_features_is_equal - equality test for two features
> + * @features1: the first features (can be NULL)
> + * @features2: the second features (can be NULL)
> + *
> + * Returns: true if they're equal, false if they're not or either are NULL
> + */
> +bool aa_features_is_equal(aa_features *features1, aa_features *features2)
> +{
> +	return features1 && features2 &&
> +	       strcmp(features1->string, features2->string) == 0;
> +}
> diff --git a/parser/features.h b/parser/features.h
> index 100f460..a0c177f 100644
> --- a/parser/features.h
> +++ b/parser/features.h
> @@ -28,5 +28,6 @@ int aa_features_new_from_kernel(aa_features **features);
>  aa_features *aa_features_ref(aa_features *features);
>  void aa_features_unref(aa_features *features);
>  const char *aa_features_get_string(aa_features *features);
> +bool aa_features_is_equal(aa_features *features1, aa_features *features2);
>  
>  #endif /* __AA_FEATURES_H */
> diff --git a/parser/policy_cache.c b/parser/policy_cache.c
> index 8d34f34..27c83c1 100644
> --- a/parser/policy_cache.c
> +++ b/parser/policy_cache.c
> @@ -252,10 +252,7 @@ int setup_cache(aa_features *kernel_features, const char *cacheloc)
>  
>  	kernel_features_string = aa_features_get_string(kernel_features);
>  	if (!aa_features_new(&cache_features, cache_features_path)) {
> -		const char *cache_features_string;
> -
> -		cache_features_string = aa_features_get_string(cache_features);
> -		if (strcmp(kernel_features_string, cache_features_string) != 0) {
> +		if (!aa_features_is_equal(kernel_features, cache_features)) {
>  			if (write_cache && cond_clear_cache) {
>  				if (create_cache(cacheloc, cache_features_path,
>  						 kernel_features_string))
>