add chaos testing

1 files changed, 43 insertions, 0 deletions

diff --git a/src/chaos.c b/src/chaos.c
new file mode 100644
index 0000000..231c94a
--- /dev/null
+++ b/src/chaos.c
@@ -0,0 +1,43 @@
+/*
+ * src/chaos.c
+ * (c) 2021 Jonas Gunz <himself@jonasgunz.de>
+ * License: MIT
+ */
+
+/**
+ * Randomly inject errors in library functions to check resiliency
+ */
+
+#if defined(_CHAOS) && defined(_GNU_SOURCE)
+
+#warning "CHAOS Mode enabled"
+
+#include <dlfcn.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+void* malloc (size_t size) {
+	int fd;
+	uint16_t rand;
+
+	void* (*realmalloc)(size_t size) =
+		(void* (*)(size_t size)) dlsym(RTLD_NEXT, "malloc");
+
+	fd = open("/dev/urandom", O_RDONLY);
+	read(fd, &rand, 2);
+	close(fd);
+
+	if( rand < 1000 ) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	return realmalloc(size);
+}
+
+#endif