There are three logging levels for messages: FATAL, NOTICE and DEBUG.
When a message is logged with FATAL level it results in bpfilter
usermode helper termination.
Introduce struct context to avoid use of global objects and store there
the logging parameters: log level and log sink.
Signed-off-by: Dmitrii Banshchikov <me@xxxxxxxxxxxxx>
---
net/bpfilter/Makefile | 2 +-
net/bpfilter/bflog.c | 29 +++++++++++++++++++++++++++++
net/bpfilter/bflog.h | 24 ++++++++++++++++++++++++
net/bpfilter/context.h | 16 ++++++++++++++++
4 files changed, 70 insertions(+), 1 deletion(-)
create mode 100644 net/bpfilter/bflog.c
create mode 100644 net/bpfilter/bflog.h
create mode 100644 net/bpfilter/context.h
diff --git a/net/bpfilter/Makefile b/net/bpfilter/Makefile
index cdac82b8c53a..874d5ef6237d 100644
--- a/net/bpfilter/Makefile
+++ b/net/bpfilter/Makefile
@@ -4,7 +4,7 @@
#
userprogs := bpfilter_umh
-bpfilter_umh-objs := main.o
+bpfilter_umh-objs := main.o bflog.o
userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi
ifeq ($(CONFIG_BPFILTER_UMH), y)
diff --git a/net/bpfilter/bflog.c b/net/bpfilter/bflog.c
new file mode 100644
index 000000000000..2752e39060e4
--- /dev/null
+++ b/net/bpfilter/bflog.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Telegram FZ-LLC
+ */
+
+#define _GNU_SOURCE
+
+#include "bflog.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "context.h"
+
+void bflog(struct context *ctx, int level, const char *fmt, ...)
+{
+ if (ctx->log_file &&
+ (level == BFLOG_LEVEL_FATAL || (level & ctx->log_level))) {
+ va_list va;
+
+ va_start(va, fmt);
+ vfprintf(ctx->log_file, fmt, va);
+ va_end(va);
+ }
+
+ if (level == BFLOG_LEVEL_FATAL)
+ exit(EXIT_FAILURE);
+}
diff --git a/net/bpfilter/bflog.h b/net/bpfilter/bflog.h
new file mode 100644
index 000000000000..4ed12791cfa1
--- /dev/null
+++ b/net/bpfilter/bflog.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Telegram FZ-LLC
+ */
+
+#ifndef NET_BPFILTER_BFLOG_H
+#define NET_BPFILTER_BFLOG_H
+
+struct context;
+
+#define BFLOG_IMPL(ctx, level, fmt, ...) bflog(ctx, level, "bpfilter: " fmt, ##__VA_ARGS__)
+
+#define BFLOG_LEVEL_FATAL (0)
+#define BFLOG_LEVEL_NOTICE (1)
+#define BFLOG_LEVEL_DEBUG (2)
+
+#define BFLOG_FATAL(ctx, fmt, ...) \
+ BFLOG_IMPL(ctx, BFLOG_LEVEL_FATAL, "fatal error: " fmt, ##__VA_ARGS__)
+#define BFLOG_NOTICE(ctx, fmt, ...) BFLOG_IMPL(ctx, BFLOG_LEVEL_NOTICE, fmt, ##__VA_ARGS__)
+#define BFLOG_DEBUG(ctx, fmt, ...) BFLOG_IMPL(ctx, BFLOG_LEVEL_DEBUG, fmt, ##__VA_ARGS__)
+
+void bflog(struct context *ctx, int level, const char *fmt, ...);
+
+#endif // NET_BPFILTER_BFLOG_H
diff --git a/net/bpfilter/context.h b/net/bpfilter/context.h
new file mode 100644
index 000000000000..e85c97c3d010
--- /dev/null
+++ b/net/bpfilter/context.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Telegram FZ-LLC
+ */
+
+#ifndef NET_BPFILTER_CONTEXT_H
+#define NET_BPFILTER_CONTEXT_H
+
+#include <stdio.h>
+
+struct context {
+ FILE *log_file;
+ int log_level;
+};
+
+#endif // NET_BPFILTER_CONTEXT_H
--
2.25.1
