Re: [PATCH] Add kernel-version dependent configuration directory

[Alexey Gladkov <gladkov.alexey@gmail.com>]

On Wed, Feb 26, 2020 at 11:04:49AM +0300, Anton V. Boyarshinov wrote:
> In some cases it looks reasonable to have kernel-version dependent
> modules configuration: blacklists, options and so on. This commit
> introduces additional configuration directories:
> * /lib/modprobe.d/`uname -r`
> * /etc/modprobe.d/`uname -r`
> 
> Signed-off-by: Anton V. Boyarshinov <boyarsh@altlinux.org>
> ---
>  libkmod/libkmod-config.c |  5 +----
>  libkmod/libkmod.c        | 44 ++++++++++++++++++++++++++++++++++++----
>  man/modprobe.d.xml       |  2 ++
>  3 files changed, 43 insertions(+), 8 deletions(-)
> 
> diff --git a/libkmod/libkmod-config.c b/libkmod/libkmod-config.c
> index aaac0a1..5cc348a 100644
> --- a/libkmod/libkmod-config.c
> +++ b/libkmod/libkmod-config.c
> @@ -711,11 +711,8 @@ static bool conf_files_filter_out(struct kmod_ctx *ctx, DIR *d,
>  
>  	fstatat(dirfd(d), fn, &st, 0);
>  
> -	if (S_ISDIR(st.st_mode)) {
> -		ERR(ctx, "Directories inside directories are not supported: "
> -							"%s/%s\n", path, fn);
> +	if (S_ISDIR(st.st_mode))
>  		return true;
> -	}
>  
>  	return false;
>  }
> diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
> index 69fe431..1ebdeb4 100644
> --- a/libkmod/libkmod.c
> +++ b/libkmod/libkmod.c
> @@ -225,6 +225,21 @@ static char *get_kernel_release(const char *dirname)
>  	return p;
>  }
>  
> +static char *get_ver_config_path(const char * dir)
> +{
> +	struct utsname u;
> +	char *ver_conf;
> +	static const char appendix[] = "modprobe.d";
> +
> +	if (uname(&u) < 0)
> +		return NULL;
> +
> +	if (asprintf(&ver_conf, "%s/%s/%s", dir, appendix, u.release) < 0)
> +		return NULL;
> +
> +	return ver_conf;
> +}
> +
>  /**
>   * kmod_new:
>   * @dirname: what to consider as linux module's directory, if NULL
> @@ -251,7 +266,7 @@ KMOD_EXPORT struct kmod_ctx *kmod_new(const char *dirname,
>  {
>  	const char *env;
>  	struct kmod_ctx *ctx;
> -	int err;
> +	int err, configs_count;
>  
>  	ctx = calloc(1, sizeof(struct kmod_ctx));
>  	if (!ctx)
> @@ -269,9 +284,30 @@ KMOD_EXPORT struct kmod_ctx *kmod_new(const char *dirname,
>  	if (env != NULL)
>  		kmod_set_log_priority(ctx, log_priority(env));
>  
> -	if (config_paths == NULL)
> -		config_paths = default_config_paths;
> -	err = kmod_config_new(ctx, &ctx->config, config_paths);
> +	if (config_paths == NULL) {
> +		char **tmp_config_paths = malloc(sizeof(default_config_paths) +
> +				sizeof(char *) * 2);
> +		if(tmp_config_paths == NULL) {
> +			ERR(ctx, "could not create versioned config.\n");
> +			goto fail;
> +		}
> +
> +		memcpy(tmp_config_paths, default_config_paths, sizeof(default_config_paths));
> +
> +		configs_count = sizeof(default_config_paths) / sizeof(char *);

Is it ARRAY_SIZE ?

> +		tmp_config_paths[configs_count-1] = get_ver_config_path("/lib");
> +		tmp_config_paths[configs_count] = get_ver_config_path("/etc");

Please use SYSCONFDIR. All other parts of the code use it.

> +		tmp_config_paths[configs_count+1] = NULL;
> +
> +		err = kmod_config_new(ctx, &ctx->config, (const char * const*) tmp_config_paths);
> +
> +		free(tmp_config_paths[configs_count-1]);
> +		free(tmp_config_paths[configs_count]);
> +		free(tmp_config_paths);
> +	}
> +	else
> +		err = kmod_config_new(ctx, &ctx->config, config_paths);
> +
>  	if (err < 0) {
>  		ERR(ctx, "could not create config\n");
>  		goto fail;
> diff --git a/man/modprobe.d.xml b/man/modprobe.d.xml
> index 211af84..d1e254a 100644
> --- a/man/modprobe.d.xml
> +++ b/man/modprobe.d.xml
> @@ -41,7 +41,9 @@
>  
>    <refsynopsisdiv>
>      <para><filename>/lib/modprobe.d/*.conf</filename></para>
> +    <para><filename>/lib/modprobe.d/`uname -r`/*.conf</filename></para>
>      <para><filename>/etc/modprobe.d/*.conf</filename></para>
> +    <para><filename>/etc/modprobe.d/`uname -r`/*.conf</filename></para>
>      <para><filename>/run/modprobe.d/*.conf</filename></para>
>    </refsynopsisdiv>
>  
> -- 
> 2.21.0
> 
> 

-- 
Rgrds, legion