[PATCH v3] Add kernel-version dependent configuration directory

["Anton V. Boyarshinov" <boyarsh@xxxxxxxxxxxx>]

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@xxxxxxxxxxxx>
---
Changes from v1: ARRAY_SIZE and SYSCONFDIR macros are used

Changes from v2: dirname honored

libkmod/libkmod-config.c |  5 +----
 libkmod/libkmod.c        | 42 ++++++++++++++++++++++++++++++++++++----
 man/modprobe.d.xml       |  2 ++
 3 files changed, 41 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..51b2e58 100644
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -225,6 +225,19 @@ static char *get_kernel_release(const char *dirname)
 	return p;
 }
 
+static char *get_ver_config_path(const char * confdir, char * modulesdir)
+{
+	char *ver_conf;
+	char * kversion = strrchr(modulesdir, '/');
+	if(kversion == NULL)
+		return NULL;
+
+	if (asprintf(&ver_conf, "%s/modprobe.d/%s", confdir, kversion+1) < 0)
+		return NULL;
+
+	return ver_conf;
+}
+
 /**
  * kmod_new:
  * @dirname: what to consider as linux module's directory, if NULL
@@ -251,7 +264,7 @@ 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 +282,30 @@ 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 = ARRAY_SIZE(default_config_paths);
+		tmp_config_paths[configs_count-1] = get_ver_config_path("/lib", ctx->dirname);
+		tmp_config_paths[configs_count] = get_ver_config_path(SYSCONFDIR, ctx->dirname);
+		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