From fd51d7bac97fc57370b0d908a7740c4ff934cd3f Mon Sep 17 00:00:00 2001
From: Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
Date: Sun, 2 Apr 2017 02:33:20 +0200
Subject: [PATCH] refactoring: kernel_has_version() => kernel_get_version() +
 version_cmp()

---
 include/villas/kernel/kernel.h | 11 +++++------
 lib/kernel/kernel.c            |  8 +++-----
 src/node.c                     |  3 ++-
 3 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/include/villas/kernel/kernel.h b/include/villas/kernel/kernel.h
index b8a54af81..5956c01b3 100644
--- a/include/villas/kernel/kernel.h
+++ b/include/villas/kernel/kernel.h
@@ -11,6 +11,9 @@
 
 #include <stdint.h>
 
+/* Forward declarations */
+struct version;
+
 //#include <sys/capability.h>
 
 /** Check if current process has capability \p cap.
@@ -38,12 +41,8 @@ int kernel_set_nr_hugepages(int nr);
  */
 int kernel_get_cmdline_param(const char *param, char *buf, size_t len);
 
-/** Check if kernel is version is sufficient
- *
- * @retval 0 Kernel version is sufficient.
- * @reval <>0 Kernel version is not sufficient.
- */
-int kernel_has_version(int maj, int min);
+/** Get the version of the kernel. */
+int kernel_get_version(struct version *v);
 
 /** Checks if a kernel module is loaded
  *
diff --git a/lib/kernel/kernel.c b/lib/kernel/kernel.c
index f4969ef62..07bdcbc8d 100644
--- a/lib/kernel/kernel.c
+++ b/lib/kernel/kernel.c
@@ -87,19 +87,17 @@ int kernel_module_loaded(const char *module)
 	return ret;
 }
 
-int kernel_has_version(int maj, int min)
+int kernel_get_version(struct version *v)
 {
 	struct utsname uts;
-	struct version current;
-	struct version required = { maj, min };
 
 	if (uname(&uts) < 0)
 		return -1;
 
-	if (version_parse(uts.release, &current))
+	if (version_parse(uts.release, v))
 		return -1;
 
-	return version_cmp(&current, &required) < 0;
+	return 0;
 }
 
 int kernel_get_cmdline_param(const char *param, char *buf, size_t len)
diff --git a/src/node.c b/src/node.c
index 06350cadc..acd4feb7a 100644
--- a/src/node.c
+++ b/src/node.c
@@ -89,7 +89,8 @@ int main(int argc, char *argv[])
 		BLD(MAG(__DATE__)), BLD(MAG(__TIME__)));
 
 	/* Checks system requirements*/
-	if (kernel_has_version(KERNEL_VERSION_MAJ, KERNEL_VERSION_MIN))
+	struct version kver, reqv = { KERNEL_VERSION_MAJ, KERNEL_VERSION_MIN };
+	if (kernel_get_version(&kver) == 0 && version_cmp(&kver, &reqv) < 0)
 		error("Your kernel version is to old: required >= %u.%u", KERNEL_VERSION_MAJ, KERNEL_VERSION_MIN);
 
 	signals_init(quit);