Add new function to work on kernel version.

This patch adds a new file containing a function that can be used
to compare the version number of the running kernel with a specific
version.

src/Makefile.am

@@ -305,6 +305,7 @@ util-hash.c util-hash.h \
 util-hashlist.c util-hashlist.h \
 util-hash-lookup3.c util-hash-lookup3.h \
 util-host-os-info.c util-host-os-info.h \
+util-host-info.c util-host-info.h \
 util-ioctl.h util-ioctl.c \
 util-ip.h util-ip.c \
 util-logopenfile.h util-logopenfile.c \

src/util-host-info.c

@@ -0,0 +1,106 @@
+/* Copyright (C) 2014 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * \file
+ *
+ * \author Eric Leblond <eric@regit.org>
+ *
+ * Get information on running host
+ *
+ */
+
+#include "suricata-common.h"
+#include "config.h"
+
+#ifndef OS_WIN32
+#include <sys/utsname.h>
+
+#define VERSION_REGEX "^([0-9]+)\\.([0-9]+)"
+
+int SCKernelVersionIsAtLeast(int major, int minor)
+{
+    struct utsname kuname;
+    pcre *version_regex;
+    pcre_extra *version_regex_study;
+    const char *eb;
+    int opts = 0;
+    int eo;
+#define MAX_SUBSTRINGS 3 * 6
+    int ov[MAX_SUBSTRINGS];
+    int ret;
+    int kmajor, kminor;
+    const char **list;
+
+    /* get local version */
+    if (uname(&kuname) != 0) {
+        SCLogError(SC_ERR_INVALID_VALUE, "Invalid uname return: %s",
+                   strerror(errno));
+        return 0;
+    }
+
+    SCLogDebug("Kernel release is '%s'", kuname.release);
+
+    version_regex = pcre_compile(VERSION_REGEX, opts, &eb, &eo, NULL);
+    if (version_regex == NULL) {
+        SCLogError(SC_ERR_PCRE_COMPILE, "pcre compile of \"%s\" failed at offset %" PRId32 ": %s", VERSION_REGEX, eo, eb);
+        goto error;
+    }
+
+    version_regex_study = pcre_study(version_regex, 0, &eb);
+    if (eb != NULL) {
+        SCLogError(SC_ERR_PCRE_STUDY, "pcre study failed: %s", eb);
+        goto error;
+    }
+
+    ret = pcre_exec(version_regex, version_regex_study, kuname.release,
+                    strlen(kuname.release), 0, 0, ov, MAX_SUBSTRINGS);
+
+    if (ret < 0) {
+        SCLogError(SC_ERR_PCRE_MATCH, "Version did not cut");
+        goto error;
+    }
+
+    if (ret < 3) {
+        SCLogError(SC_ERR_PCRE_MATCH, "Version major and minor not found (ret %d)", ret);
+        goto error;
+    }
+
+    pcre_get_substring_list(kuname.release, ov, ret, &list);
+
+    kmajor = atoi(list[1]);
+    kminor = atoi(list[2]);
+
+    pcre_free_substring_list(list);
+
+    if (kmajor > major)
+        return 1;
+    if (kmajor == major && kminor >= minor)
+        return 1;
+error:
+    return 0;
+}
+
+#else /* OS_WIN32 */
+
+int SCKernelVersionIsAtLeast(int major, int minor)
+{
+    SCLogError(SC_ERR_NOT_SUPPORTED, "OS compare is not supported on Windows");
+    return 0;
+}
+
+#endif /* OS_WIN32 */

src/util-host-info.h

@@ -0,0 +1,29 @@
+/* Copyright (C) 2014 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * \file
+ *
+ * \author Eric Leblond <eric@regit.org>
+ */
+
+#ifndef __UTIL_HOST_INFO_H__
+#define __UTIL_HOST_INFO_H__
+
+int SCKernelVersionIsAtLeast(int major, int minor);
+
+#endif /* __UTIL_HOST_INFO_H__ */