1 files changed, 67 insertions, 0 deletions
diff --git a/usr/src/lib/lib9p/common/log.c b/usr/src/lib/lib9p/common/log.c
new file mode 100644
index 0000000000..fb2596a16f
--- /dev/null
+++ b/usr/src/lib/lib9p/common/log.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2016 Jakub Klama <jceel@FreeBSD.org>
+ * All rights reserved
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted providing that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include "log.h"
+
+static const char *l9p_log_level_names[] = {
+	"DEBUG",
+	"INFO",
+	"WARN",
+	"ERROR"
+};
+
+void
+l9p_logf(enum l9p_log_level level, const char *func, const char *fmt, ...)
+{
+	const char *dest = NULL;
+	static FILE *stream = NULL;
+	va_list ap;
+
+	if (stream == NULL) {
+		dest = getenv("LIB9P_LOGGING");
+		if (dest == NULL)
+			return;
+		else if (!strcmp(dest, "stderr"))
+			stream = stderr;
+		else {
+			stream = fopen(dest, "a");
+			if (stream == NULL)
+				return;
+		}
+	}
+
+	va_start(ap, fmt);
+	fprintf(stream, "[%s]\t %s: ", l9p_log_level_names[level], func);
+	vfprintf(stream, fmt, ap);
+	fprintf(stream, "\n");
+	fflush(stream);
+	va_end(ap);
+}