kexec: Move kernel_version into the kexec core

I'm not pleased with the hacks that we use kernel_version
for but kernel_version itself is reasonable code and might
be needed elsewhere, so move kernel_version into the kexec
core.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/kexec/kernel_version.c b/kexec/kernel_version.c
new file mode 100644
index 0000000..079312b
--- /dev/null
+++ b/kexec/kernel_version.c
@@ -0,0 +1,58 @@
+#include "kexec.h"
+#include <errno.h>
+#include <string.h>
+#include <sys/utsname.h>
+#include <string.h>
+#include <limits.h>
+#include <stdlib.h>
+
+long kernel_version(void)
+{
+	struct utsname utsname;
+	unsigned long major, minor, patch;
+	char *p;
+
+	if (uname(&utsname) < 0) {
+		fprintf(stderr, "uname failed: %s\n", strerror(errno));
+		return -1;
+	}
+
+	p = utsname.release;
+	major = strtoul(p, &p, 10);
+	if (major == ULONG_MAX) {
+		fprintf(stderr, "strtoul failed: %s\n", strerror(errno));
+		return -1;
+	}
+
+	if (*p++ != '.') {
+		fprintf(stderr, "Unsupported utsname.release: %s\n",
+			utsname.release);
+		return -1;
+	}
+
+	minor = strtoul(p, &p, 10);
+	if (major == ULONG_MAX) {
+		fprintf(stderr, "strtoul failed: %s\n", strerror(errno));
+		return -1;
+	}
+
+	if (*p++ != '.') {
+		fprintf(stderr, "Unsupported utsname.release: %s\n",
+			utsname.release);
+		return -1;
+	}
+
+	patch = strtoul(p, &p, 10);
+	if (major == ULONG_MAX) {
+		fprintf(stderr, "strtoul failed: %s\n", strerror(errno));
+		return -1;
+	}
+
+	if (major >= 256 || minor >= 256 || patch >= 256) {
+		fprintf(stderr, "Unsupported utsname.release: %s\n",
+			utsname.release);
+		return -1;
+	}
+
+	return KERNEL_VERSION(major, minor, patch);
+}