1 files changed, 96 insertions, 0 deletions
diff --git a/lib/util/logging.c b/lib/util/logging.c
new file mode 100644
index 0000000..7ad21d7
--- /dev/null
+++ b/lib/util/logging.c
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include <bpf/libbpf.h>
+#include <xdp/libxdp.h>
+
+#include "logging.h"
+#include "util.h"
+
+static enum logging_print_level log_level = LOG_INFO;
+
+static int print_func(enum logging_print_level level, int indent,
+		      const char *format, va_list args)
+{
+	int i;
+	if (level > log_level)
+		return 0;
+
+	for (i = 0; i < indent; i++)
+		fprintf(stderr, " ");
+
+	return vfprintf(stderr, format, args);
+}
+
+static int libbpf_print_func(enum libbpf_print_level level, const char *format,
+			     va_list args)
+{
+	return print_func(level + 1, 2, format, args);
+}
+
+static int libbpf_silent_func(__unused enum libbpf_print_level level,
+			      __unused const char *format,
+			      __unused va_list args)
+{
+	return 0;
+}
+
+static int libxdp_print_func(enum libxdp_print_level level, const char *format,
+			     va_list args)
+{
+	return print_func(level + 1, 1, format, args);
+}
+
+static int libxdp_silent_func(__unused enum libxdp_print_level level,
+			      __unused const char *format,
+			      __unused va_list args)
+{
+	return 0;
+}
+
+#define __printf(a, b) __attribute__((format(printf, a, b)))
+
+__printf(2, 3) void logging_print(enum logging_print_level level,
+				  const char *format, ...)
+{
+	va_list args;
+
+	va_start(args, format);
+	print_func(level, 0, format, args);
+	va_end(args);
+}
+
+void init_lib_logging(void)
+{
+	libbpf_set_print(libbpf_print_func);
+	libxdp_set_print(libxdp_print_func);
+}
+
+void silence_libbpf_logging(void)
+{
+	if (log_level < LOG_VERBOSE)
+		libbpf_set_print(libbpf_silent_func);
+}
+
+void silence_libxdp_logging(void)
+{
+	if (log_level < LOG_VERBOSE)
+		libxdp_set_print(libxdp_silent_func);
+}
+
+enum logging_print_level set_log_level(enum logging_print_level level)
+{
+	enum logging_print_level old_level = log_level;
+
+	log_level = level;
+	return old_level;
+}
+
+enum logging_print_level increase_log_level(void)
+{
+	if (log_level < LOG_VERBOSE)
+		log_level++;
+	return log_level;
+}