1 files changed, 122 insertions, 0 deletions
diff --git a/src/log.c b/src/log.c
new file mode 100644
index 0000000..e54f8fc
--- /dev/null
+++ b/src/log.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2018-2021 Yubico AB. All rights reserved.
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#undef _GNU_SOURCE /* XSI strerror_r() */
+
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "fido.h"
+
+#ifndef FIDO_NO_DIAGNOSTIC
+
+#define XXDLEN	32
+#define XXDROW	128
+#define LINELEN	256
+
+#ifndef TLS
+#define TLS
+#endif
+
+static TLS int logging;
+static TLS fido_log_handler_t *log_handler;
+
+static void
+log_on_stderr(const char *str)
+{
+	fprintf(stderr, "%s", str);
+}
+
+static void
+do_log(const char *suffix, const char *fmt, va_list args)
+{
+	char line[LINELEN], body[LINELEN];
+
+	vsnprintf(body, sizeof(body), fmt, args);
+
+	if (suffix != NULL)
+		snprintf(line, sizeof(line), "%.180s: %.70s\n", body, suffix);
+	else
+		snprintf(line, sizeof(line), "%.180s\n", body);
+
+	log_handler(line);
+}
+
+void
+fido_log_init(void)
+{
+	logging = 1;
+	log_handler = log_on_stderr;
+}
+
+void
+fido_log_debug(const char *fmt, ...)
+{
+	va_list args;
+
+	if (!logging || log_handler == NULL)
+		return;
+
+	va_start(args, fmt);
+	do_log(NULL, fmt, args);
+	va_end(args);
+}
+
+void
+fido_log_xxd(const void *buf, size_t count, const char *fmt, ...)
+{
+	const uint8_t *ptr = buf;
+	char row[XXDROW], xxd[XXDLEN];
+	va_list args;
+
+	if (!logging || log_handler == NULL)
+		return;
+
+	snprintf(row, sizeof(row), "buf=%p, len=%zu", buf, count);
+	va_start(args, fmt);
+	do_log(row, fmt, args);
+	va_end(args);
+	*row = '\0';
+
+	for (size_t i = 0; i < count; i++) {
+		*xxd = '\0';
+		if (i % 16 == 0)
+			snprintf(xxd, sizeof(xxd), "%04zu: %02x", i, *ptr++);
+		else
+			snprintf(xxd, sizeof(xxd), " %02x", *ptr++);
+		strlcat(row, xxd, sizeof(row));
+		if (i % 16 == 15 || i == count - 1) {
+			fido_log_debug("%s", row);
+			*row = '\0';
+		}
+	}
+}
+
+void
+fido_log_error(int errnum, const char *fmt, ...)
+{
+	char errstr[LINELEN];
+	va_list args;
+
+	if (!logging || log_handler == NULL)
+		return;
+	if (strerror_r(errnum, errstr, sizeof(errstr)) != 0)
+		snprintf(errstr, sizeof(errstr), "error %d", errnum);
+
+	va_start(args, fmt);
+	do_log(errstr, fmt, args);
+	va_end(args);
+}
+
+void
+fido_set_log_handler(fido_log_handler_t *handler)
+{
+	if (handler != NULL)
+		log_handler = handler;
+}
+
+#endif /* !FIDO_NO_DIAGNOSTIC */