Squashed 'external/toxcore/c-toxcore/' content from commit 67badf69

git-subtree-dir: external/toxcore/c-toxcore
git-subtree-split: 67badf69416a74e74f6d7eb51dd96f37282b8455

other/bootstrap_daemon/src/log_backend_syslog.c

@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later
+ * Copyright © 2016-2018 The TokTok team.
+ * Copyright © 2015-2016 Tox project.
+ */
+
+/*
+ * Tox DHT bootstrap daemon.
+ * Syslog logging backend.
+ */
+#include "log_backend_syslog.h"
+
+#include "global.h"
+
+#include "../../../toxcore/ccompat.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <syslog.h>
+
+void log_backend_syslog_open(void)
+{
+    openlog(DAEMON_NAME, LOG_NOWAIT | LOG_PID, LOG_DAEMON);
+}
+
+void log_backend_syslog_close(void)
+{
+    closelog();
+}
+
+static int log_backend_syslog_level(LOG_LEVEL level)
+{
+    switch (level) {
+        case LOG_LEVEL_INFO:
+            return LOG_INFO;
+
+        case LOG_LEVEL_WARNING:
+            return LOG_WARNING;
+
+        case LOG_LEVEL_ERROR:
+            return LOG_ERR;
+    }
+
+    return LOG_INFO;
+}
+
+void log_backend_syslog_write(LOG_LEVEL level, const char *format, va_list args)
+{
+    va_list args2;
+
+    va_copy(args2, args);
+    int size = vsnprintf(nullptr, 0, format, args2);
+    va_end(args2);
+
+    assert(size >= 0);
+
+    if (size < 0) {
+        return;
+    }
+
+    char *buf = (char *)malloc(size + 1);
+    vsnprintf(buf, size + 1, format, args);
+
+    syslog(log_backend_syslog_level(level), "%s", buf);
+    free(buf);
+}