Move logging functions to log.c

Instead of keeping all unrelated to
C/R procedure helpers in util.c move
logging related helpers to log.c.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

log.c

@@ -0,0 +1,69 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <limits.h>
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <errno.h>
+
+#include <fcntl.h>
+
+#include "compiler.h"
+#include "types.h"
+#include "util.h"
+
+/*
+ * Note pr_ helpers rely on this
+ * descriptor!
+ */
+static int logfd = STDERR_FILENO;
+
+int get_logfd(void)
+{
+	return logfd;
+}
+
+int init_log(const char *name)
+{
+	struct rlimit rlimit;
+	int fd = STDERR_FILENO;
+
+	if (name) {
+		fd = open(name, O_CREAT | O_WRONLY);
+		if (fd == -1) {
+			pr_perror("Can't create log file %s\n", name);
+			return -1;
+		}
+	}
+
+	if (getrlimit(RLIMIT_NOFILE, &rlimit)) {
+		pr_err("can't get rlimit: %m\n");
+		return -1;
+	}
+
+	logfd = rlimit.rlim_cur - 1;
+	if (dup2(fd, logfd) < 0) {
+		pr_err("can't duplicate descriptor %d->%d: %m\n",
+			fd, logfd);
+		logfd = STDERR_FILENO;
+		return -1;
+	}
+
+	return 0;
+}
+
+void fini_log(void)
+{
+	if (logfd != STDERR_FILENO &&
+	    logfd != STDIN_FILENO &&
+	    logfd != STDERR_FILENO)
+		close(logfd);
+
+	logfd = STDERR_FILENO;
+}